Aude Bolopion

Christian Stolle

Robert Tunnell

Sinan Haliyo

Stéphane Régnier

Sergej Fatikow

* A Bolopion

Remote Microscale Teleoperation through Virtual Reality and Haptic Feedback

This paper reports the remote handling of microscale objects, between two sites approximately 630 km distant. To manipulate objects less than 10 µm, specific equipments such as AFM (Atomic Force Microscope) cantilevers integrated into a SEM (Scanning Electron Microscope) are generally required. Enabling remote access to such a system would benefit any micro/nanoresearcher. However, vision feedback and sensor data of a micromanipulation system are generally limited, hence the implementation of a teleoperation scenario is not straightforward. Specific tools are proposed here for an intuitive manipulation in a wide range of applications. To ensure ease of manipulation, both a 3D virtual representation of the scene and haptic feedback are provided. Force sensor feedback is limited since only two measures are available. In order to extend this information, vision algorithms are developed to estimate the respective positions of the tool and objects, which are then used to calculate the haptic feedback. The stability of the overall scheme is very sensitive to time delays. This requirement is taken into account in vision algorithms and the communication module which transfers the data between the two remote sites. In addition, the proposed robotic control architecture is modular so that the platform can be used for a wide range of applications. First results are obtained on a teleoperation between Paris, France, and Oldenburg, Germany.

I. INTRODUCTION

Teleoperation offers the possibility to perform remote manipulations. In particular it is widely used to interact with hostile environments [START_REF] Muhammad | Development of water hydraulic remote handling system for divertor maintenance of ITER[END_REF], [START_REF] Peñín | Force reflection for time-delayed teleoperation of space robots[END_REF]. Another advantage is to allow a highly trained operator to remotely perform the operation. This case is of particular importance in surgical procedures [START_REF] Marescaux | Transcontinental robot assisted remote telesurgery: feasibility and potential applications[END_REF]. Researchers in the field of micro and nanomanipulation would also benefit from these systems which would allow them to access rare and specific equipments such as AFM (Atomic Force Microscope) cantilevers integrated into a SEM (Scanning Electron Microscope).

Intuitivity of such a system is a key parameter for their use in a wide variety of applications and by a large number of researchers. Visual feedback is thus a first requirement. Providing haptic feedback is also a promising solution as it enables operators to feel interactions between the tool 4 Place Jussieu, 75005 Paris, France. {bolopion, haliyo, regnier}@isir.upmc.fr 2 christian.stolle@uni-oldenburg.de and the rest of the manipulation zone, including the to be manipulated objects [START_REF] Guthold | Controlled manipulation of molecular samples with the nanoManipulator[END_REF], [START_REF] Bukusoglu | Haptic manipulation of microspheres using optical tweezers under the guidance of artificial force fields[END_REF].

For the visual feedback, images from microscopes are commonly used. To provide effective visual feedback virtual reconstruction of the scene can be provided in addition to optical or scanning electron microscope images [START_REF] Ammi | Robotic assisted micromanipulation system using virtual fixtures and metaphors[END_REF]. However, most of these displays are only 2D [START_REF] Kim | Task-based and stable telenanomanipulation in a nanoscale virtual environment[END_REF]. 3D reconstruction would provide a better immersion of the user on the scene.

To compute haptic feedback, information about the scene must be known. However, force sensing is limited since when using a cantilever tool, only two deformations measurements are available [START_REF] Sitti | Teleoperated touch feedback from the surfaces at the nanoscale: modeling and experiments[END_REF]. To provide 3D haptic feedback several solutions have been proposed. In particular, physics models are used [START_REF] Li | Development of augmented reality system for AFM-based nanomanipulation[END_REF], [START_REF] Vogl | Augmented reality user interface for an atomic force microscope-based nanorobotic system[END_REF], [START_REF] Onal | Teleoperated 3-D force feedback from the nanoscale with an atomic force microscope[END_REF]. Alternatively, strategies are defined from the available measurements to compute haptic guides to perform a given task [START_REF] Bolopion | 2D micro teleoperation with force feedback[END_REF], [START_REF] Bolopion | Haptic teleoperation for 3D microassembly of spherical objects[END_REF]. However, most of these methods either assume precise knowledge about the environment, or are specific to a particular task. The solution proposed here is to use vision tracking [START_REF] Sievers | Real-time object tracking for the robotbased nanohandling in a scanning electron microscope[END_REF] to update a virtual reconstruction of the scene in real-time. The image patterns required for tracking are provided during the system calibration phase in a teach in process.

Another concern is the stability of the teleoperation system. Haptic coupling schemes' stability is highly sensitive to time delays [START_REF] Boukhnifer | Wave-based passive control for transparent micro-teleoperation system[END_REF]. Solutions based on passivity have been proposed, but are not optimal for microscale since they deteriorate transparency [START_REF] Onal | Teleoperated 3-D force feedback from the nanoscale with an atomic force microscope[END_REF]. The whole system should thus be designed to minimize time delays.

Several issues must thus be addressed to provide new tools for intuitive manipulation for a wide range of applications:

1) the robotic control architecture must be organized to enable a wide variety of applications, and should minimize the communication delays, 2) the vision algorithm must provide information about the scene, and be adapted to SEM images. The update rate must be compatible with haptic stability requirements, 3) the vision data should not saturate the network by heavy load transmission, and users should be provided with an intuitive 3D display of the scene, 4) the haptic feedback must be designed according to available information, and the coupling should be transparent and stable. These issues are addressed on this paper. This work is based on previous studies on the design of the experimental setup [START_REF] Mick | Combined nanorobotic AFM/SEM system as novel toolbox for automated hybrid analysis and manipulation of nanoscale objects[END_REF] and the software architecture [START_REF] Stolle | Distributed control architecture for automated nanohandling[END_REF] and on analyzes of haptic coupling schemes [START_REF] Bolopion | Analysis of stability and transparency for nanoscale force feedback in bilateral coupling[END_REF]. The remote handling is implemented between the Microrobotics and Control Engineering division (AMIR) of Univ. Oldenburg, Germany and the Institut des Systèmes Intelligents et de Robotique (ISIR) of Univ. Pierre et Marie Curie, Paris, France. The micromanipulation setup, situated in Oldenburg, is composed of an AFM (Atomic Force Microscopy) manipulator integrated in an SEM to combine the performances of cantilever based manipulation to the vision capabilities of scanning electron microscopes [START_REF] Mick | Combined nanorobotic AFM/SEM system as novel toolbox for automated hybrid analysis and manipulation of nanoscale objects[END_REF]. So that researchers get access to this rare equipment, a remote teleoperation system is implemented in Paris, where microscale teleoperation is a well studied topic [START_REF] Bolopion | Haptic teleoperation for 3D microassembly of spherical objects[END_REF]. This platform is composed of a haptic interface and a virtual reality room. This paper is organized as follows. The experimental setup is presented in Section II. Section III details the robotic control architecture. Algorithms for vision detection and tracking are detailed in Section IV. These data are used to determine the haptic feedback and the update of the virtual scene as detailed in Section V. Experimental results are given in Section VI. Section VII concludes the paper.

II. MICROSCALE TELOPERATION SYSTEM

The micromanipulation setup is composed of a commercially available piezoresistive contact type cantilever 1 with a stiffness of 4 N.m -1 . Vertical forces applied on the cantilever are translated into a change in resistance and measured as voltage change. Voltage measurements are made using an amplifier 2 and a 16-bit analog digital converter 3 . Due to the design of the cantilever, the resolution of torsional forces is low, and do not provide accurate enough information to compute haptic feedback. SEM images will be used to compensate for this lack of force measurement. To increase 1 SSI-SS-ML-PRC400, Seiko Instruments 2 Hottinger Baldwin Messtechnik GmbH 3 NI-PCI-6259, National Instruments the field of view, the head part of the cantilever has been cut thinner by a focused ion beam (FIB).

The cantilever is used to manipulate commercially available melanin microspheres 4 (diameter: 1 -2 µm) loosely deployed on a silicon plate (5 mm x 5 mm). It is mounted on the fine positioning part of a nanorobotic setup [START_REF] Mick | Combined nanorobotic AFM/SEM system as novel toolbox for automated hybrid analysis and manipulation of nanoscale objects[END_REF]. This positioning part is piezo driven with a build-in capacitive position sensors for closed-loop movement control and high accuracy positioning 5 . Its lateral stroke is up to 100 µm and the z-range is up to 50 µm and the positioning accuracy is at the lower nanometer scale. The specimen holder has been mounted on a coarse positioning unit. This unit consists of three slip stick driven, orthogonal mounted linear axes 6 . These positioners are equipped with optical positioning sensors allowing for travel ranges of several centimeters with a repositioning accuracy up to 50 nm.

The whole setup is placed in a high-resolution scanning electron microscope with a Schottky-emitter 7 that is also equipped with a FIB column8 and a gas injection system.

Researchers are situated in Paris (France). They teleoperate the cantilever through an Omega haptic device 9 . This master arm is a 3 degrees of freedom device for both displacement and haptic feedback. To avoid damages of the haptic interface forces higher than 3 N are truncated. Users are immersed in a virtual reality room which comprises a 3D display module in addition to the haptic device. A reconstructed image of the scene is projected in stereoscopic 3D on a 1.80 × 2.4 m 2 screen.

Position and force data are exchanged between the two distant sites by a communication module described in Section III.

III. REMOTE COMMUNICATION AND SOFTWARE ARCHITECTURE

In order that the teleoperation system remains stable, the robotic control system must be designed to minimize time delays. It should also be modular to enable a wide variety of applications. To meet these requirements, it is based on the distributed control system for automated micro-and nano robotics (DCAAN) [START_REF] Stolle | Distributed control architecture for automated nanohandling[END_REF]. It consists in several servers written in C++ which are connected via CORBA (Common Object Request Broker Architecture) based on a TCP/IP network. The servers are categorized into three roles, low level control server (Lolec), sensor provider (Sepro) and a high level control program (Hilec). Lolecs are responsible for executing automation process primitives for a single robot such as "move to position xy". Sepros provide sensor data to all Lolecs or Hilecs on a push basis. A Sepro sends new data as soon as it is available or at a minimum update interval. Hilec [START_REF] Jasper | Towards automated robotic nanomanipulation systems[END_REF] is an automation server, which processes Python-based scripts. In these automation scripts the process primitives offered by all connected Lolecs and Sepros can be used.

Due to the distributed nature of the tele-control task the software has been subdivided into two parts (see Fig. 2). The one located in Paris is the operator side, and the one in Oldenburg is the manipulation setup. At the remote side three different programs are running:

• the Sepro Olvis is responsible for processing image based information such as video streams [START_REF] Wortmann | Image processing architecture for real-time micro-and nanohandling applications[END_REF]. The Olvis framework runs on a Quad Core I7 Intel computer. It is directly connected via local area network with the SEM control computer in Oldenburg. To ensure modularity, it can be configured by combining algorithms in a graph like structure. Depending on these algorithms different kinds of information such as sphere and cantilever positions can be derived (see Section IV). Olvis and Hilec share a common graphical user interface (GUI) for displaying image processing graphs and live images at various processing stages. The GUI also provides all functions of an integrated development environment for automation scripts, • the AFMLolec is processing the tele-control commands by moving the cantilever tip to the target position and sending an estimation of the actual position and a measure of the force back in return. The control of the AFM itself is realized in hardware [START_REF] Mick | Combined nanorobotic AFM/SEM system as novel toolbox for automated hybrid analysis and manipulation of nanoscale objects[END_REF]. The AFMLolec is capable of processing primitives and translates them into hardware control signals,

• the SEMLolec enables in particular the operator to turn the experimental setup towards the focus of the SEM by moving the SEM stage, and to change image parameters such as brightness and contrast. These settings are indeed of primary importance to ensure efficient vision tracking. At the operator side the virtual reality server and the OmegaLolec is located. The OmegaLolec server forms the heart of the operator side software and provides a small user interface which enables the operator to initialize and calibrate the system as well as to monitor information such as force and position of the cantilever. In addition to the numerical display a live SEM image (see Section IV) can be provided to the operator via the GUI. The OmegaLolec is also responsible for translating the force and position feedback of the AFM-cantilever and forces and positions of the haptic device into each other. The positional updates of the cantilever and the sphere are managed by the OmegaLolec.

The communication between the operator and the remote sides has been realized directly via UDP packages. The communication delay has been measured by the means of the round trip time (RTT) by requesting the current position of the cantilever 100 times. The average RTT has been determined at 37 ms, the minimum RTT at 36 ms and the maximum RTT at 39 ms. The distributed control system enables to minimize RTT, and to ensure modularity. It is thus suitable to perform a wide range of teleoperation over important distances.

IV. IMAGE PROCESSING AND TRACKING

Due to the lack of force measurement, images from the SEM are used to get information about the scene. Tracking algorithms must be adapted to the specificity of SEM images, and the update rate must be sufficient to meet the requirements of haptic feedback. Images are acquired with a resolution of 627 x 627 pixels. The view field of the handling scene is in the range of 10 to 100 µm.

The cantilever is tracked with a template matching algorithm (TM) [START_REF] Goshtasby | A two-stage cross-correlation approach to template matching[END_REF], which is one of the fastest and the most common real-time marker tracking approaches. It finds the position in the image with the best correspondence with the template. To achieve good tracking requirements, a mark has been structured by the FIB at the top of the cantilever (Fig. 3(a)). This mark is used as the template for the TM, and its unique features enable to precisely determine the position of the cantilever. In the initialization step the mark is tagged manually. Automated detection will be considered in future works. To calculate the position of the cantilever tip, a offset is added to the position of the tracking mark. To be used in teleoperation, the update rate of the position of the cantilever has to be as fast as possible. Therefore the process is set to the highest priority in the Olvis framework to achieve an update rate of up to 50 Hz.

The melanin spheres are tracked with a cross correlation (CC) based template matching approach. This algorithm is developed to especially meet the requirements of object tracking in the SEM. In particular, the algorithm integrates SEM parameters like view field to achieve a magnification invariant tracking. The tracking of the melanin spheres is more difficult in contrast to the cantilever because the appearance of the spheres change during the handling (Fig. 3). The cantilever shadows the spheres due to position changes, which modifies the intensity and contrast of the image. Due to the view angle depended detector shadowing effects and different brightness and texture features of the spheres, it was decided to work on edge images to generate reliable results. The CC is modified to use specially generated templates. After applying the edge detection filter a CC is used to find the spheres. In contrast to normal CC binary ring templates are used. These ring templates are specially generated to fit to the contour of a circle, independently of the texture values of the sphere. Their radii depend on the diameter of the spheres, which minimum and maximum values are supposed to be known from the product specifications. Therefore, a list of ring templates with different radii and ring widths are automatically generated and passed to the CC. The number of CC cycles is equal to the number of ring templates. The result list contains all spheres of the cycles with a correlation result higher than the defined threshold for the CC. At the end, the result list is clustered and the weighted center points are calculated. The clustering is necessary because the same sphere can be detected multiple on a slightly different position in each CC cycle.

To meet the teleoperation requirements, the detection should be fast. However, in order to avoid a slowdown of the cantilever tracking, the positions of the melanin spheres are calculated with a low priority in the Olvis framework. This choice was made since the cantilever is moved more often than the spheres. The sphere tracking has an update rate of 3 to 8 Hz for searching in the sphere diameters in the range of 1 to 1.6 µm with an image size of 627 x 627 pixels. This tracking algorithm, as well as the one for the cantilever detection, have a sub-pixel accuracy.

During this application the involved objects were only tracked in x and y directions. The relative height of the cantilever with respect to the substrate is thus unknown. For this work, this lack of information is compensated by the force measurement, which estimates the vertical force applied on the cantilever and enables to determine if the tip is or not in contact with the substrate or an object.

Other solutions might include a calibration step, or image processing based on the distance between the tip and its shadow on the substrate.

V. INTUITIVE TELEOPERATION ENVIRONMENT

To provide an intuitive environment of manipulation, both visual and haptic feedback are proposed. They are based on both force measurement and vision tracking of the tool and the objects.

A. Virtual Reality Scene

To fit haptic feedback requirements, communication delays and thus the amount of data to transfer should be limited to strict minimum. Vision data represents the heaviest load on the network. In the case studied here where the distance between the operator and the manipulator is several hundreds kilometers, the synchronicity between the seeing and handling can only be guaranteed by avoiding the communication delay. This is ensured by an efficient software architecture (see Sec. III) and a drastic reduction on the size of data packets. The approach proposed here avoids to send over the complete camera output and replaces it with an immersive virtual reality scene, presented in stereoscopic 3D. Instead of transmitting the complete image, only the cantilever's and the closest object's positions are sent over using respectively the sensor feedback of piezo actuators and vision tracking. Considering that this data represents only 2 × 3 × 64 bits (doubles), the gain compared to the transmission of a full frame video image is enormous. In addition to save transmission bandwidth, this approach also replaces the SEM image which lacks perspective and intuitive depth information by an easier-to-interpret 3D reproduction.

The virtual reality scene of the micromanipulator is constructed using Blender, an open source 3D content creation suite [START_REF]Blender[END_REF]. It is easily extensible using Python programming language, includes Bullet real-time physics engine and can produce stereoscopic output. The scene includes the AFM tip used as the manipulation tool and a sphere as the manipulated object. In that work, it was decided to represent only the sphere closest to the cantilever tip. This facilitates the manipulation for untrained users by displaying only important information on the reconstructed scene. The scene is constructed setting 1 Blender unit as 1 µm and is depicted in Fig 1 . All along the operation, the user has complete freedom to modify the camera position and zoom.

The drawback of this method is the requirement of prior knowledge of geometries and dimensions and an initial calibration process between real image and virtual reality frames. As in this case the cantilever's and manipulated objects' geometries are perfectly known and their virtual models are created prior to the operation, it is sufficient to map their real positions to the virtual scene. Details such as the precise shape of the objects, or their exact dimensions are not represented in the virtual scene. However, this information is not necessary for a manipulation task.

In order to calibrate the real and the virtual cantilever positions, the real cantilever is moved to the contact with substrate, then its vertical position is adjusted such as its flexion is null, without snapping the tip off the surface. This position is offset as the (0, 0, 0) on the virtual scene. The object position is obtained from image processing along with the tip position. As all the projection lines in a SEM image are parallel, the resulting image is an orthographic projection. Considering that all the objects are on the same plane, i.e lying on the substrate where the angle of substrate plane and image plane is known, their respective 3D positions can be calculated with fixed z. The tip and object image positions is then used to calibrate those initial positions with the reference positions of the virtual scene.

During the manipulation and after the calibration, the VR engine receives periodically positions of the cantilever and the manipulated object and updates them respectively. If a delay in communication appears such as the VR frame rate is higher than the data transmission rate, the included Bullet physics engine extrapolates the positions. This extrapolation is not expected to reproduce faithfully the real physics. As a new updated position is received the object jumps to the position, the Bullet engine minimizes this behavior and leads to a smoother user experience. Also note that over several experiences, this extrapolation approach was called upon extremely rarely.

B. Haptic Feedback

In addition to 3D display of the scene, haptic feedback is proposed to provide intuitive manipulation tools. Users control the cantilever through a haptic interface, and feel forces which give them information about the scene. The haptic coupling connects the haptic device to the manipulation tool (Fig. 4). Users interact with the master device by applying a force F op on it to control the slave device. The desired position of the tip P t is set using the position of the haptic handle P h , scaled by a factor α p . Since the workspace of this arm is limited, a clutching function has been implemented so that users can set the haptic handle to a desired position without moving the cantilever [START_REF] Dominjon | The "Bubble" technique: interacting with large virtual environments using haptic devices with limited workspace[END_REF]. Operators feel a haptic force F h derived from both force measurements and the vision algorithm.

Force measurements, obtained by the flexion of the AFM probe, are used to compute the vertical haptic force f z h transmitted to users. It is computed from the vertical force f t applied on the tip, scaled by a factor α f : f z h = α f f t . To compute the haptic force in the (x, y) plane (substrate plane), vision algorithms are used. They enable to determine the respective position of the tool (P t ) and the sphere (P s ). This force is based only on the distance to the closest sphere. Indeed, simplifying the scene enables the user to concentrate on the manipulation task. Other scenario considering all the objects in a close neighborhood of the tool could be proposed.

As explained in Section IV, the vectors P t ) and P s are of dimension 2×1 in the (x, y) plane. Based on that information, a repulsive haptic force is computed. This repulsion would push away the tool from the spheres in the horizontal plane and avoid involuntary contact. This force is based on the distance between the tool and the object:

D = d x d y = p x t -p x s p y t -p y s (1)
where D = d x 2 + d y 2 is the distance between the sphere and the tip, and d x (resp. d y ) are the coordinates along the x (resp. y) axis. Based on that distance, a repulsive force field is computed. While the distance D is greater than a given threshold R int , the force is null since it is considered that the tip is far enough from the sphere. When this distance becomes less than the threshold, a non null repulsive force f r is computed:

f r = 1.0 -D R int f max if D < R int 0 else (2)
where f max is the maximum force that would be sent for D = 0. This value will never be reached since the minimum distance between the tip and the center of the sphere cannot be less then the radius of the object. This force enables users to know when they are entering the interaction radius, and to estimate the relative position of the tip and the sphere for spheres of a given dimension. Moreover, by setting the threshold value equal or slightly superior to the radius of the object, it would also be possible to let the user feel solely the contact in the horizontal plane between the tip and the object.

The force sent to the haptic device is computed by projecting f r along the x and y axes, proportionally to d x and d y . f z h is given by measurements of the tip deflection as explained above:

F h =   f x h f y h f z h   =    d x D f r d y D f r α f f t    (3)
If the tip is not in contact with the substrate ( f t = 0) the haptic feedback is null. In that work, it is considered that if the tip is above the substrate, users cannot collide with spheres. Alternatively, a given height under which force feedback is activated could be defined to take into account the sphere height. This height could be determined in realtime using vision information, such as the distance between the tip and its shadow.

VI. EXPERIMENTAL RESULTS

To validate the tools developed, experiments are conducted. The first task performed is in an approach-retract experiment. It consists in approaching the cantilever towards the substrate, making contact, applying a force on the substrate, and then retracting. This is used for educational purposes, to give users a better understanding of nanoscale phenomena [START_REF] Marliere | Multi-sensorial interaction with a nano-scale phenomenon: The force curve[END_REF], or to perform indentation or patterning tasks [START_REF] Onal | A scaled bilateral control system for experimental one-dimensional teleoperated nanomanipulation[END_REF]. In this work, this simple 1D task enables to test the robotic control architecture and the stability of the haptic feedback. There is no display of the virtual scene. Vision algorithms are not used since only the vertical force is of interest: the transpose of the haptic force is computed as F h T = 0 0 α f f t . Results are depicted in Fig. 5. The haptic force is represented as a function of time and as a function of the position of the cantilever. The system remains stable for that experiment. The haptic feedback enables users to know when the cantilever is in contact with the substrate, and to estimate the effort applied on the substrate since the haptic force is proportional to the flexion (hence the vertical displacement) of the cantilever.

Before performing manipulations of objects, it is necessary to get information about their position with respect to the tool. A visual display of the 3D reconstructed virtual reality scene is provided (Fig. 6). Repulsive haptic force field are also transmitted to users based on measurements from the tip deflection combined with vision algorithms (Eq . 3).

Results are depicted in Fig. 7. The position of the sphere as well as the trajectory of the tip are represented. Haptic force on the plane of the substrate is given for several points. This force tends to keep the tip away from the spheres, and enable users to localize precisely the objects. For the sake of clarity, Fig. 6. Teleoperation of microspheres using a haptic interface, with 3D virtual reconstruction of the manipulation scene. This image is presented in stereoscopic 3D to the user who can move the camera at will. the vertical force is not depicted. It is similar to the one of the approach-retract experiment. Performances of the system are summarized in Table I. The developed tools enable the intuitive manipulation of an AFM integrated into an SEM from a remote site, that can be situated hundreds of kilometers from the setup. Both visual and haptic feedback are provided.

VII. CONCLUSION

In that work, new tools have been developed to enable intuitive manipulation of microscale objects from geographically distant sites. Ease of manipulation is ensured by visual and haptic feedbacks. Force measurements are limited while using a cantilever simultaneously as the manipulation and sensing tool. Therefore vision detection and robust tracking algorithms with respect to SEM image issues, such as shadowing, are used to get additional information about the scene. They enable the 3D reconstruction of the manipulation area, displayed in stereoscopic view. Haptic feedback is based on both the vision tracking and force measurements. Stability of haptic feedback is addressed by minimizing delays using efficient vision algorithms and robotic control architecture. The modularity of the control system also enables a wide variety of applications.

To widen the range of applications, nanometer size objects should be considered. Other equipments, such as grippers, should also be integrated, and associated strategies to derive intuitive haptic feedback and calibration of the virtual scene should be proposed. Next step will consist in moving the spheres, for example by pushing them with the cantilever. The same visual and haptic feedback will be used, but a special care will be taken to define the manipulation strategy. Several issues, such as sticking effects, must be addressed to perform this manipulation [START_REF] Onal | Visual servoing-based autonomous 2-D manipulation of microparticles using a nanoprobe[END_REF].

This work is a first step towards teleoperation systems enabling intuitive manipulation of micro or nanoscale objects between geographically distant sites. These systems will offer great opportunities for researchers, giving them access to rare equipments.

Fig. 1 .

 1 Fig. 1. Teleoperation between Paris, France, and Oldenburg, Germany (630 km point-to-point distance).

Fig. 2 .

 2 Fig. 2. Software architecture and communication layout between the remote side in Oldenburg and the operator side in Paris

  (a) Cantilever with the FIB structured tracking mark and detected melanin spheres. (b) 273 spheres were detected without any fail detection.

Fig. 3 .

 3 Fig. 3.These images show the diversity of image characteristics of the spheres and the related detection problems (shadowing, contrast and intensity modifications, ...).

Fig. 4 .

 4 Fig. 4. Haptic coupling.

Fig. 5 .

 5 Fig. 5. Approach-retract experiment. Scaling factors are set to: α p = 4800, α f = 1.10 6 .

Fig. 7 .

 7 Fig. 7. Sphere avoidance: repulsive haptic force field. Haptic coupling gains for the force computation are set to: R int = 5 µm, f max = 4 N, α f = 1.10 6 and α p = 4800. The magnitude of the force vectors is proportional to the distance between the tip and the object (note that x and y scales are different).

TABLE I PERFORMANCES

 I OF THE SYSTEM

	Item	Performances
	Transmission	RTT: 36 -39 ms, average: 37 ms
	Vision tracking	sphere: 3 -8 Hz
		cantilever: 50 Hz
	Virtual reality	3D visual reconstruction
		data load: 2 × 3 × 64 bits
	Haptic	force measurement: contact tool/substrate
		vision: distance tool/object

Micro Particles GmbH

Physikinstrumente GmbH

SmarAct GmbH

Lyra2, Tescan

Canion, Orsay-Physics

Force Dimension, http://www.forcedimension.com

VIII. ACKNOWLEDGMENTS

Parts of this work have been funded by the European project FIBLYS and by the project PROCOPE (DAAD-Egide). Special thanks to Uwe Mick for the technical and scientific support.


Dr Frederik Dhondt

Stanislas De Skarbimierz

Pierre-Marie Dupuy

Vincent Chetail

History in Legal Doctrine. Vattel and Réal de Curban on the Spanish Succession

History in Legal Doctrine. Vattel and Réal de Curban on the War of the Spanish Succession.

According to the classical theory of international law, international obligations are the consequence of state consent. 1 In the hierarchy of binding norms, international treaties concluded between two primary subjects of law 2 occupy the most prominent position. Next, international custom, or common normative understandings 3 based on a continuous state practice and 'general principles of law recognized by civilized nations'. Finally, only as a subsidiary means for the determination of rules of law, 'judicial decisions and the teachings of the most highly qualified publicists of the various nations ' (art. 38(1) ICJ Statute). 4 When legal scholars systematise the normative environment into a theoretical framework, they tend to give coherence to what traditionally is rather chaotic, as the list of sources above already indicates. The purpose of their writing is de lege ferenda. Concepts and classifications can be taken over by states in creating new law, or by international and national courts and tribunals, interpreting international law. 5 Doctrine can thus generate future international law. This explains why most courses on international law still contain a part on 'Big Names', such as Vittoria, Grotius, Isidorus of Sevilla or Lauterpacht. 6 Legal historians should look behind the surface of the 'Big Names' canon. Our current selection of prominent doctrinal figures is arbitrary. 7 Second-rank authors might have been unjustly left out or forfotten. The selection made in the 'Classics of International Law' 8 series, published by the Carnegie Endowment in the early twentieth century, was a translation of academics' preferences and thus the actual 'usefulness' of doctrine for legal interpretation. The present contribution leaves this question aside and focuses on context, establishing an 'inventory of differences', rather than a continuous taxonomy of concepts over time. 9 First, I will set the stage for this contribution, introducing the War of the Spanish Succession, a conflict symbolising the culmination of dynastic conflict at the end of Louis XIV's Grand Siècle. 10 Next, select cases from the war will be approached as they appear in the works of two emblematic eighteenth-century scholars, Réal de Curban and Vattel.

I. Setting the Stage

A. Fighting For Supremacy in Europe: Habsburg v. Bourbon

The War of the Spanish Succession, fought from about 1701-1702 to 1713-1714, fundamentally reconfigured the European chessboard. [START_REF] Vault | Mémoires militaires relatifs à la succession d'Espagne sous Louis XIV extraits de la correspondance de la Cour et des généraux rev[END_REF] Archduke Charles of Austria (1685-1740) faced Philip of Anjou (1683-1740), grandson of Louis XIV (1638-1715) [START_REF] Bély | Louis XIV le plus grand roi du monde[END_REF] in a struggle with continent-wide and even global implications 13 . Philip conquered the crown of Spain, but had to cede considerable parts of the Spanish composite monarchy [START_REF]La pérdida de Europa. La guerra de Sucesión por la Monarquía de España[END_REF] to his Habsburg competitor, who had been elected Emperor in 1711. [START_REF] Otmar Von Aretin | Kaisertradition und österreichische Grossmachtpolitik[END_REF] Present-day Belgium (minus Liège), the Southern Netherlands, came under Austrian rule, [START_REF] Van Gelder | Tien jaar trial-and-error ? De opbouw van het Oostenrijks bewind in de Zuidelijke Nederlanden[END_REF] just as Naples [START_REF] Spagnoletti | Il dibattito politico a Napoli sulla Successione di Spagna[END_REF] or Milan. Spain welcomed a Bourbon monarch, [START_REF]La présence des Bourbons en Europe, XVI e -XXI e siècle[END_REF] Gibraltar became British, [START_REF] Conn | Gibraltar in British Diplomacy in the Eighteenth Century[END_REF] Catalonia and Scotland were absorbed. Hundreds of thousands of soldiers and civilians died. In the middle run, the war ended a century of bloodshed and brought a point of rest in the secular confrontation between Bourbon and Habsburg monarchs. [START_REF] Corvisier | Présence de la guerre au XVII e siècle[END_REF] I previously argued that the discussion on the succession in Spain was an example of a broader shift from mainly private law-dependent argumentation to an autonomous system of horizontal and bottom-up constructed public international law. [START_REF] Dhondt | Law on the Diplomatic Stage: the 1725 Ripperda Treaty[END_REF] This element has been often ignored by historians. The War of the Spanish succession was at the same time inevitable and avoidable. The eventual partition of European monarchies agreed to in 1713-1714 followed the logic of earlier partition treaties in 1697-1700, [START_REF] Rule | The Partition Treaties, 1698-1700: A European View[END_REF] and even of an almost fifty-year old secret partition between Louis XIV and Leopold I in 1668. [START_REF] Bérenger | Une tentative de rapprochement entre la France et l'Empereur[END_REF] No monarch could dominate Europe. The composite Spanish monarchy was to be split up in order to preserve the European State System as a whole. In that sense, the Peace of Utrecht was far more important than the Peace of Westphalia, concluded at a time where conflict was still raging on between Spain and France. [START_REF] Steiger | Rechtliche Strukturen der europäischen Staatenordnung 1648-1792[END_REF] Consequently, all conflicting rules of a municipal nature, even the most fundamental ones, could be cast aside. [START_REF] Dhondt | Équilibre et hiérarchie : l'argument juridique dans la diplomatie française et anglaise après la Paix d'Utrecht[END_REF] However, this style of reasoning seemed to have been limited to diplomatic practice alone. Legal theory lived in a different world. Christian Wolff 26 or Emer de Vattel are seen as authors of natural law. [START_REF] De | Le droit des gens, ou, Principes de la loi naturelle[END_REF] B. Réal and Vattel: Erudition v. Philosophy ?

The impact of the War of the Spanish Succession was so considerable across Europe, that it could hardly have escaped legal authors a generation later 28 . My attention was immediately drawn by the narrative techniques used in doctrine since humanism. [START_REF] Prevost | Mos Gallicus jura docendi. La réforme humaniste de la formation des juristes[END_REF] The use of historical examples can be seen as a technique to invalidate improbable argumentation drawn from authority-reasoning, such as as the famous Donatio Constantini. 30 Yet, the use of history can also be instrumental, in order to support a thesis brought forward by an author from his own, subjective point of view. 31 The relationship between history and legal writing is complex. Traditionally, the critical study of authentic documents enabling a reliable account of legal precedent is associated with humanism. However, by the eighteenth century, historiography had been split up according to two different approaches. On the one hand, erudites assembled verifiable piles of knowledge. On the other hand, philosophers as Voltaire (1694-1778) 32 , or, later in the eighteenth century, Turgot or Condorcet used history as a theoretical reflection on the past. 33 In his Discours préliminaire to the Encyclopédie, d'Alembert derided erudition, as a quality of the reproductive mind, lacking originality or utility for society. 34 In the words of La Bruyère :

'des esprits, si je l'ose dire, inférieurs et subalternes, qui ne semblent faits que pour être le recueil, le registre ou le magasin de toutes les productions des autres génies.' 35 The two authors selected in this contribution, Gaspard Réal de Curban (1682-1752) and Emer de Vattel (1714-1767), had the 'bad luck' to be overshadowed by two main Enlightenment thinkers. Voltaire thought that Réal was outright boring, Rousseau had far a far bigger audience than his contemporary Vattel. Réal de Curban has received scant attention in historiography 36 and is often loathed as a compiler, similar to bureaucrats as Nicolas-Louis Le Dran (1687-1774). 37 His contemporary Mably (1709-1785) (Siam, Soumission, 44.). See also Jean-Mattieu Mattéi's elaborate treatment of Réal and his doctrinal comparison with his eighteenth century contemporaries : Histoire du droit de la guerre, 1700-1819 : introduction à l'histoire du droit international ; avec une biographie des principaux auteurs de la doctrine internationaliste de l'Antiquité à nos jours (Aix-en-Provence : PUAM, 2006). Mattéi attributes the exclusion of natural law from international law to Réal's introductory distinctions (Ibid., 230 nothing but laudatory remarks on Réal's treatment of the law of nations. 39 Réal omitted important areas, such as maritime law, but this did not make up for his fine and -foremost-practically useful treatment of embassies, war or treaty law. 40 Albeit… with a zest of French chauvinism. 41 Precisely this remark by Ompteda shows how sensitive the Spanish Succession still was. Vattel's work is the next in von Ompteda 42 's standard review of literature. The latter perfectly demonstrates how all chapters in Vattel conform to those of Wolff's analysis of the law of nations. [START_REF] Dhondt | VATTEL's Le droit des gens[END_REF] However, although the Neuchatelian diplomat and writer seems to limit himself to a mere transposal of Wolff's Latin writings into the more accessible French, it is clear that Vattel dropped essential elements, such as Wolff's Civitas Maxima, or the collective organ of the society of States. 44 Moreover, Ompteda expressed his frustration with Vattel's superficiality. 45 The author proclaimed to be writing for statesmen and diplomats. Well, then, why not illustrate the general theory of Wolff by: 'Beyspiele und Beweise aus der Geschichte, besonders der neueren, zu erlaütern und zu unterstützen suchet, als worunter sich Real sehr gegen ihn auszeichnet.' [START_REF]Vattel diesen Vorzug seinem Werke gegeben, und es dadurch practischer gemachet, so würde es gewiss noch weit grösseren Nuzen nach sich ziehen, und sich noch weit mehr in den händen der Grossen und überhaupt dererjenigen befinden, vond enen die practische Ausübung des Völkerrechts abhänget.' 47 Dominique Gaurier[END_REF] Present-day judgements on Vattel are more nuanced. The author, 'un diplomate qui […] avance […] ses opinions personnelles 47 ', foresaw the necessary pragmatic handles in his manuscript. He did not conceive of natural law as a top-down ordained command on subjects. Consequently, the virtue of the sovereigns (who did feel concerned), would automatically restrain even the most ferocious beasts among the crowned heads of Europe, and bring them to measure and reason, in order not to forfeit their reputation. [START_REF] Vattel | [END_REF] What cannot be denied, however, is his clearly subjective oriented discourse towards France and the Pope. Writing as the legal counsel of an independent multi-confessional republic, 49 Vattel, son of a Calvinist minister 50 , consistently argued in favour of self-determination and filled his work with anti-Popish, [START_REF] Vattel | tyranny of Philip II of Spain exerted on his Protestant subjects[END_REF] anti-Imperial 52 or anti-French innuendo. 53 The supplementary value of the oath accompanying a treaty is the object of Vattel's irony. Only in remote ages of obscurity and ignorance did men believe they were bound by oath, subject to Papal intervention and annulation: 54 'Les enfans mêmes savent aujourd'hui, que le serment ne constituë point l'obligation de garder une Promesse ou un Traité : il prête seulement une nouvelle force à cette obligation, en y faisant intervenir le nom de Dieu. Un homme sensé, un honnête-homme, ne se croit pas moins lié par sa parole seule, par sa foi donnée, que s'il y avoit ajouté la religion du serment.' 55 At some instances, Vattel committed lapidary factually inaccurate assertions. E.g. when he described the French invasion of the Southern Netherlands in 1667, at the occasion of the War of Devolution. According to the Neuchatelian author, 'LOUÏS XIV. étoit au milieu des Païs-bas, avant que l'on sçut en Espagne qu'il prétendoit à la Souveraineté d'une partie de ces riches Provinces, du chef de la Reine son Epouse'. 56 This assessment was not entirely correct: French claims were already very well known for years by the time of Louis' invasion. 57 France insisted on the payment of Queen Marie Thérèse (1638-1683)'s dowry and linked this to the validity of her renunciation sworn as Spanish Infanta, based on cause theory in contract law and natural law. A consistent pamphlet accompanying the invasion listed all claims based on customary inheritance rules in the Southern Netherlands. 58 Vattel was extremely subjective on conference diplomacy as well. From 1712 to 1730, Europe knew no less than five successive multilateral conferences: Utrecht, Baden, Brunswick, Cambrai and Soissons. 59 They were dismissed as : 'ennuyeuses comedies, jouées sur le théâtre politique ; & dans lesquelles les principaux Acteurs se proposoient moins de faire un accommodement, que de paroître le désirer.' 60 International guarantees, the backbone of the European State System after the Peace of Utrecht (1713), were brought into question by Vattel, since 'they are always conceived as subsidiary to the rights of Ibid., Ch. XIV, §179: affirmation according to which Protestant members of the Holy Roman Empire have a twice as populous as their Catholic counterparts; Ibid., Ch. XIV, §155: Roman Catholic clergy imposing taxes on fresh husbands to obtain the right to sleep with their wives in the first three nights after the ceremony, with reference to a Réglement du Parlement of 19 March 1409 and Montesquieu's Esprit des Loix, cynically noting that those clearly were 'les nuits qu'il falloit choisir; on n'auroit pas tiré grand argent des autres.'; Ibid., Ch XII, § § 150-151: complaints on the jurisdictional competence and immunities of the clergy, and on the injustice of the celibacy ( § 140, 149). 52 Vattel, B. II, Ch. III, § 41: royalty liberated the House of Brandenburg from serfdom under the House of Habsburg. 53 Vattel, B. I, Ch. XII, 57, § 144: the ambition of popes and clerics is fuelled by the 'superstition des peuples'; B. I, Ch. IV, § 39: 'ces impôts accablants, dont les deniers sont dissipés par un luxe ruïneux, ou livrés à des Maitresses & à des Favoris.' ; Ibid., Ch. XX, §242, ridiculing the Parliament of Paris, humbly remonstrating to the French King on formal aspects of Royal legislation. 54 third parties'. To be more specific: if France guaranteed Charles VI's Pragmatic Sanction in 1735, 61 this obligation was rendered void by the fact that the document violated the rights the Elector of Bavaria Charles Albert of Wittelsbach (1697-1745), a French ally, claimed on the basis of his marriage with a daughter from the preceding Emperor. 62 As far as treaties were concerned, the lex posterior-principle did not count for Vattel. 63 This clearly is no example of impartial and abstract legal reasoning. The relative brevity of Vattel's historical exempla prevents the development or comparison of specific argumentation and harms the credibility of his theoretical statements. In the following section, I compare his and Réal's interpretation of events and legal argumentation during and after the War of the Spanish Succession, and confront them with evidence from diplomatic sources where applicable.

II. The War of the Spanish Succession as an Historical Fundgrube

The use of contemporary exempla in legal doctrine was made possible by the abundance of eighteenth century publications on military conflicts. It would be an overstatement to see in the War of the Spanish Succession the birth of European public opinion. 64 However, in contrast to the situation in the early seventeenth century, when Grotius composed his De iure belli ac pacis, the reliability of published treaty collections had already been established. 65 from that of Louis XIV and William of Orange, but still had explicit assumptions on the major war that closed the seventeenth century.

A. Réal: Justifying French Behaviour 'Comment les princes éviteront-ils ces fautes, s'ils ne connoissent pas tous les devoirs attachés à la Royauté ? Comment seront-ils instruits de ces devoirs, si personne ne prend soin de les leur expliquer ?' Réal de Curban, La Science du Gouvernement, B. I, Discours préliminaire

(1) Catalonia Réal de Curban treated the -still controversial-example of Catalonia's status within the Spanish state. The Spanish monarchy was in essence a composite structure of personal unions. At the end of the fifteenth century, the marriage of Queen Isabella I of Castile (1451-1504) and King Ferdinand II of Aragon (1452-1516) brought two already composite entities together. The crown of Aragon, ruled by Ferdinand, comprised the Kingdom of Majorca, Valencia, Sardinia, Sicily, Naples… and the principality of Catalonia, a reference to the conglomerate of territories ruled initially by the counts of Barcelona. The coming to power of Philip V, grandson of Louis XIV, caused a major constitutional revolution in Spain. Whereas the different crowns had stood for separate types of local privileges and customs, the new monarch imposed a uniform model.

During the war, Philip had been far more popular in the crown of Castile than in that of Aragon. His main contender, Archduke Charles of Habsburg, had even held a full-fledged court in Barcelona. 68 On 20 June 1705, Britain concluded a treaty of alliance with the Estates of Catalonia. 69 On 2 July 1713, Philip V signed peace with Great Britain at Utrecht. 70 He had won the war and was now recognized by the major powers in Europe. His final reconciliation with his resentful opponent Charles, who had been crowned Holy Roman Emperor in 1711, would not come about until 1725. French military victories at Villaviciosa and Brihuega (9-10 December 1710), had driven the Austrian pretender out of most of Spain, but not out of Catalonia. An intermediate solution was found in the Convention for the Evacuation of Catalonia and the Neutrality of Italy, concluded under British mediation at the Utrecht conference on 14 March 1713, 71 weeks before the final Franco-British peace treaty. From 1711 to 1725, 72 this document remained the basis for legal relations between Charles VI and Philip V.

On 11 September 1714, Franco-Spanish troops under Marshal Berwick captured Barcelona and put an end to an ephemerous claim to sovereignty. 73 Réal de Curban cited the case as an example of bad treaty drafting. When territory was acquired by cession, the former owner had to discharge it of all 68 After his coronation as Emperor, Charles VI consequently installed a Spanish Council and a Spanish Secretary of State in Vienna, symbolizing his enduring claims on Charles II's inheritance. See Erwin Matsch, Der Auswärtige Dienst von Österreich(-Ungarn) 1720-1920(Wien 1986), 42-43. 69 ), 42-43. 69 Treaty of Alliance between Queen Anne and the principality of Catalonia against the Duke of Anjou 'La cession qu'une Puissance fait d'un pays à l'autre ne doit pas être simplement expliquée en termes généraux, elle doit être détaillée, & l'on doit faire mention expresses des noms de chaque place cédée, du tems, de la manière dont elle sera remise, & de toutes les circonstances qui y ont rapport [START_REF] Gaspard Réal De Curban | La science du gouvernement, t. 5: contenant le droit des gens, Qui traite les Ambassades; de la Guerre; des[END_REF] .' Réal referred to the political context of the Utrecht conference. France and Britain had concluded separate preliminaries of peace (8 October 1711). 76 Thus, Britain had left the alliance tying the Habsburg pretender to the Dutch Republic and most German princes. As a consequence, the French armies obtained victories against the remaining allied troops in the field, such as the battle of Denain (24 July 1712). [START_REF] Lesage | Louis XIV sauve sa mise[END_REF] The Utrecht Peace Conference was already going on at the time Austrian defeat. Yet, Charles VI's plenipotentiaries failed to agree with their French counterparts at the conference. Charles refused to sign a peace dictated by a treacherous ally and persisted in his determination to obtain the Spanish crown. The conference broke up, and fighting resumed, until Eugene of Savoy and Marshal Villars signed a Peace Treaty in Rastatt (6 March 1714). [START_REF]Peace Treaty between Charles VI and Louis XIV[END_REF] However, before Charles VI's men left the table at Utrecht, they had signed the convention on Catalonia and Italy. Réal de Curban recalled that the agreement foresaw a peaceful evacuation by the Austrian forces. The treaty was silent on the exact modalities, and counted on the parties' good faith in the execution of this contractual obligation between sovereigns. Philip V had not negotiated this convention directly. [START_REF]Which would not stop him from accusing Charles VI of having retreated his troops not too early, as Réal reproached them, but too late[END_REF] Charles refused to treat with his opponent and thought he could only rely on the French plenipotentiaries. [START_REF] Réal | [END_REF] Réal deplored this, and would have preferred a clause stating that Spanish troops could simultaneously enter the city through the gates at the other end of town when the Austrians left. In reality, the Austrians had cleared Barcelona three weeks before the Spanish could enter the town. [START_REF] De | Histoire militaire du règne de Louis le Grand[END_REF] Consequently, the Estates of Catalonia decided to seize power themselves. The Austrian commander Starhemberg, instead of sticking to his duties as a subject of Charles VI, who was a party to the Convention, even allowed his soldiers to desert and serve the Catalan cause. Moreover, the commanders on the isles of Mallorca and Iviça (Ibiza) refused to recognize Philip V as King, declaring war on Louis XIV and Philip V (15 July 1713). 82 The ensuing bloody siege of Barcelona by Berwick, concluded on 11 September 1714, would not have been necessary, if this 'défaut d'attention' had been avoided from the French side… Réal treated this explicitly as a problem of bad treaty drafting, applied to the specific case of cession clauses, under the part devoted to treaty making (Chapitre III). [START_REF] Réal | [END_REF] From the internal point of view, Réal argued that inhabitants of Catalonia were not actually punished by Philip V. Their case was similar to the subjects of the crown of Aragon and Valencia. Seven years earlier, on 25 April 1707, Marshal Berwick had crushed the Austro-British-Dutch-Portuguese-Aragonese army of Charles 'III' at the battle of Almanza. 84 As a consequence, the specific fueros or privileges of those crowns had been abolished. 85 Philip V had extended the Castilian situation to his other subjects. The same operation took place in Catalonia after the fall of Barcelona.

During the Franco-Spanish war of 1718-1719, French armies invaded Catalonia and Aragon, 'pour donner occasion à ces peuples de se remettre en possession de leur libertez et de leurs privileges'. 86 In fact, the King of Spain had ignored his obligation under article XIII of the Treaty of Peace concluded with Britain in Utrecht on 11 April 1713. 87 The British had asked to safeguard the privileges of their old allies. However, once Philip V had been forced to adhere 88 to the Quadruple Alliance -a treaty concluded on 2 August 1718 in order to complement the Peace Treaties of Utrecht, Rastatt and Baden-89 the subject was not touched upon anymore. The following words of the Regent, reported by the Earl of Stair, George I (1660-1727)'s ambassador in Paris, are sufficiently clear: 'Dans 8 des mêmes conditions, l'on a ajouté aux personnes qui doivent être restituées dans leurs biens et dans leurs droits, les communautez, universitez et corps; le regent dit, que cela implique la restitution des privileges des catalans, et qu'ainsy il faut absolument le rayer, parce qu'il fait, que jamais le roy d'espagne ne consentira cette restitution.' 90 At the ensuing Peace Conference in Cambrai (1722-1725), 91 the British plenipotentiaries Polwarth and Whitworth followed Réal de Curban's interpretation. The inhabitants of Catalonia had 'forfeited a good deal of their Rights […], by their second Rebellion, and declaring War on their own account, after the Emperor was retired and had withdrawn all his forces […] and by their surrendering at last on discretion, reserving any thing further than their lives and fortunes'. 92 84 Henry Kamen, Philip V of Spain: the king who reigned twice (New Haven 2001), 59. 85 Royal Decrees of 23 June (Aragon) and 19 July 1707 (Valencia), abolishing the local legal system and declaring the Castilian laws applicable to these crowns. Réal, II, Ch. 7, S. II, XXIII, 104; Jesus Lalinde Abadia, Iniciacion historica al derecho español (Barcelona 1970), 217-218. However, in successive steps (1711-1715-1716, the socalled 'Nueva Planta'-system), Philip V allowed for the coexistence of local rules (leyes municipales) and the Law of Castile (Derecho común). E.g. in Catalonia, penal law and procedure were subject to local rules. For civil law, local law was applicable in all cases not prohibited by central legislation. E.g. the Consolato del Mar continued to be applicable in Catalonia and Mallorca. 86 Even Emperor Charles VI, who had held his personal court in Barcelona during the war, decided to give in at the Cambrai conference. 93 Moreover, at another instance, Réal de Curban came back to the Franco-Spanish military confrontations earlier in Louis XIV's reign. When invading Catalonia during the Nine Years ' War, Marshall Noailles (1650-1708) explicitly rejected proposals by the Catalans to strangle sleeping Spanish soldiers quartered at their houses. 94 Thematically, Réal used this to illustrate his point in the part devoted to ius in bello (Chapter 2). 95 The rules of war applied. Thus, proportionality and necessity restricted 'cases wherein one could attempt at the life or liberty of an enemy, or harm him'. 96 The illustration of this principle comes in a sequence classical, humanist examples going back to Antiquity. 97 (2) Gibraltar

Another controversial issue of the Spanish Succession, the fate of Gibraltar, is also seen as a technicality. Anything important should be explicitly stated. Réal proposed a hierarchy between general obligations, to be framed in the most generous terms, and specific clauses, 'pour tout ce qui est important'. 98 Since the latter are the logical consequence of the former, or the application of a general reasoning in a specific case, everything from the historical preamble (which should not be too precise, in order not to resuscitate old enmities), to treaty structure (whereby 'l'ordre des articles, doit contribuer à l'intelligence du Traité […] à bien distinguer les objets') should serve to strengthen consensus between the parties. 'Plus la foi des traités est sainte, plus aussi l'on doit écarter avec soin tout ce qui peut y donner quelque atteinte.' 99 In the case of Gibraltar, general intentions proclaimed by George I in 1721 could give Spain a vague claim to the rock. 100 The King of Great Britain had in effect uttered the following promise: 'Monsieur mon frère […] je ne ballance plus a assurer V.M. de ma promptitude à la satisfaire par raport à sa demande touchant la restitution de Gibraltar lui promettant de me servir des premieres occasions favorables p[ou] r regler cet article du Consentement de mon Parlem[en] t .' George I explicitly referred to Parliamentary assent, indicating that the King alone could not alienate possessions held by the Crown. Interestingly, Réal limited his analysis to the mere textual expression in the international treaty. British diplomats argued shortly after George's promise to return Gibraltar, that the sovereign could only have formulated this within the prevailing constitutional framework, implying the necessity of parliamentary consent permitting territorial alienation. 101 Hall (Cambridge), envoy extraordinary, then ambassador to Russia (1704-1714), at the Imperial Diet in Regensburg (1714), envoy in Berlin (1716-1717, 1719-1722), The Hague (1717-1719). MP for the Isle of Wight (1722). 93 The Imperial plenipotentiaires Windischgrätz and Penterriedter implored Luis I [Philip V's temporary successor, January-August 1724]'s 'magnanimité et Piété', but could not ignore, that Catalonia had obtained the same treatment as the most favoured subjects of Castile (Courtes Reflexions sur la Reponse de Mess rs les ambassadeurs Plenipotentiaires d'Espagne, Cambrai, 26 May 1724, NA, SP, 78, 174, f. 138v°). 94 1713) (Leiden/Boston 2015), 184-186, 193-194 and 237-239. Nevertheless, Réal did not stop at the unilateral conditionality of finding 'une occasion favorable'. 102 Britain's attitude is seen as dependent on the execution of countervailing Spanish obligations: 'la promesse a été faite dans le cours d'une négociation, & son execution paroissoit dépendre de ce que le Roi d'Espagne devoit exécuter de son côté'. 103 If we confront this with the practice of negotiation, Réal's assessment accurately reflected diplomatic positions. Britain promised the eventual restitution of Gibraltar in return for Spanish accession to the conditions of the Quadruple Alliance. Philip acceded in February 1720, but delayed the full execution of the treaty clauses. Just as his opponent, Emperor Charles VI. When Charles and Philip concluded peace in 1725, they were facing an alliance of France, Britain, the Dutch Republic and Protestant German princes 104 . Spain laid siege to Gibraltar (22 February 1727). Yet, the Austrian commitment to war was far from serious. Barely three months after the start of the siege, Peace Preliminaries were signed in Paris (31 May 1727). The Spanish monarch judged George I had broken his royal word, and carefully locked the original of the letter away in a wooden box at court. 105 Yet, Philip failed to conquer the Rock before a new international agreement was reached, and chose not to pursue the conquest as a primary objective. The siege was lifted on 6 March 1728.

(3) British Betrayal ?

Réal further developed the theory of the exceptio non adimpleti contractus when treating the inviolability of treaty promises. He started by nuancing the absolute nature of the pacta sunt servandaprinciple. 106 The necessities of international life and the changing nature of alliances had crowned selfinterest as the infallible yardstick of promises, or of treaty interpretation. Rare were the obligations interpreted according to their original ratio. 107 Yet, this did not imply that a sovereign could easily break his word. States were repeat players. Breaking one's word equalled losing one's reputation. Moral and political considerations alike excluded treaty-breakers from the Society of Nations: 'Tout Prince qui ne regarde les Traités que comme de vains fantômes qu'un instant critique a produits, & qu'un autre instant peut détruire arbitrairement au gré de l'intérêt, est non-seulement un ennemi du genre humain, mais encore un très-mauvais politique […] un Prince ne peut violer sa parole, sans perdre sa réputation.' 108 In essence, sovereigns had to stick to their word. Treaty interpretation according to subsequent practice or the necessities of international life allowed for subtleness with respect to the initial motives. However, if a treaty was reciprocal in nature, the non-execution of one's own obligations could count as a valid reaction to similar behaviour by a contracting party, just as between private persons. Sovereigns never concluded contracts alone. 109 When confronted with the non-execution of a treaty by the other party, sovereigns were excused from performing on their side. This could concern essential treaty violations, as well as accessory ones.

Loyalty to treaty promises in general did not pose a particular theoretical problem. However, the War of the Spanish Succession presented a peculiar problem. By signing the preliminaries of Peace with France in October 1711, Britain de facto deserted the Treaty of the Grand Alliance concluded with the Habsburg Emperor and the States-General of the United Provinces.110 At least, this was the opinion of Charles VI. He was left alone in his struggle against Philip V. During the Utrecht peace conference, Eugene of Savoy, Charles' most brilliant general, lost the battle of Denain. British troops did not participate in the battle. It had become clear that the French candidate for the Spanish throne could not be defeated. Britain argued that the Grand Alliance's main aim had been to procure a reasonable satisfaction for the Austrian candidate, against the excessive claim on European hegemony from the Bourbon camp. Réal sought a position in the middle, and recognised the violation of the Treaty of the Grand Alliance. He left aside whether the 'reasonable satisfaction' had been attained, and formulated accessory grounds to justify British behaviour.

Allies were under a common obligation to persist until they all agreed to terms of peace with a common enemy. Yet, exceptions to this principle existed, designed to reduce the impact of every sovereign's arbitrary veto power. It would have been unreasonable if one could prevent his alliance partners from signing a treaty, or if reasonable peace conditions were blocked time and again by one of the partners: an ally obstinately refusing to conclude peace at advantageous terms, was judged to break up the alliance. Finally, a state could not be assumed to sacrifice its essential interests to an alliance, concluded to serve the interest held in common with the other partners. Obstinate partners continuing the war effort, violated the base and spirit which grounded the actual treaty, and dispensed their contracting parties of their obligation to continue the struggle. 111 Charles VI's behaviour could well fit into the latter category. Even after the battle of Denain, the Emperor refused to sign a peace treaty in Utrecht, and decided to fight on. A series of defeats brought him to the negotiating table in November 1713, leading to the Treaties of Rastatt (6 March 1714) and Baden (7 September 1714), confirming the Utrecht agreements. In view of the construction of his work, Vattel first treated succession as a matter of internal public law. In view of the Neuchâtel situation, 112 it was clear to him that the corpus of the nation (the 'corporate people') 113 should be sovereign in deciding on the criteria for succession, as well as in the actual choice when the throne became vacant. 114 Salus populi suprema lex ! 115 According to this general rule, the testament of Charles II (1661-1700) and Maria Teresa's renunciation before the Cortes (Estates) of Castile ought to have been valid: 'Si même les Prétendants ont transigé entr'eux, ou choisi des Arbitres, la Nation n'est point obligée de se soumettre à ce qui aura été ainsi réglé, à-moins qu'elle n'ait consenti à la Transaction, ou au Compromis […] Elle ne reconnoit aucun Juge sur elle, dans une affaire où il s'agit de ses Devoirs les plus sacrés & de ses Droits les plus précieux.' 116 Attempts to divide the composite Spanish monarchy would not have found favour with Vattel, since:

'un Prince n'est point en droit de partager son Etat entre ses Enfants. Toute souveraineté proprement dite est, de sa nature, une & indivisible ; puisqu'on ne peut séparer malgré-eux ceux qui se sont unis en Société.' However, an important exception existed. In case a monarch had several federate entities under his power in a composite state, he was entitled to partition his possessions among his siblings. Albeit with the concurrence of the respective national demoi concerned. 117 In the opposite case, the monarch united in his person all majesty essentially belonging to the 'Corps entier de la Nation.' 118

(2) Renunciations and Partitions

Vattel's emphasis on popular consent was in striking contrast with contemporary diplomatic practice. The Peace Treaties of Utrecht, Rastatt and Baden, terminating the War of the Spanish Succession, were only possible after a political deal on the partition of the Spanish monarchy had been reached. Moreover, diplomats constructed an analogy with the international approbation of two other successions: the Act of Settlement (1701) voted in the English Parliament 119 and the Pragmatic Sanction (1713) issued by Emperor Charles VI. 120 Vattel's reasoning started from the opposite point of view. Renunciations pronounced by a 'Fille qui épouse un prince étranger', such as Louis XIV's wife, were in his eyes as valid as a formal law issued by the competent state organs to exclude specific persons from succeeding to the throne, 121 with reference to the English Act. For Vattel, not the interest of the ruling dynasty should predominate, but that of the political corpus in which sovereignty ultimately resided. 122 He thereby referred to the 'most learned and well-informed legal authors' of his time, echoing the conceptions of Henri François d'Aguesseau (1668-1751), future chancellor of Louis XV (1710-1774) and proctor general at the Parliament of Paris, 123 and his contemporary Joly de Fleury (1675-1756), advocate-general.

Both magistrates argued that the renunciations of Philip of Anjou, grandson of France, to the French throne, would have deprived the French people of a sovereign, by declaring a person normally entitled to succeed under the lois fondamentales, a foreigner and thus victim to exclusion under the droit d'aubaine. 124 The nation was not to be deprived of a 'petit-fils de France', who could not dispose of his right to succeed to the throne, or of the national territory. 125 'Ny le Prince peut aliéner l'Estat ni l'Estat ne peut perdre son Prince'. 126 This threatened the unicity of the transmission of the French crown. 127 More fundamentally, d'Aguesseau warned that France produced contradictory rhetoric. On the one hand, Louis' claims to the Spanish throne had always rested on the invalidity of his wife's renunciation to her father's throne. At the end of the war, however, the British rendered Philip V's recognition conditional on his own renunciation to the throne of France. Was Philip undermining the very basis of his own accession ? 128 Réal de Curban, on the other hand, completely adhered to the partition logic. In the second volume of his Science du Governement, dedicated to a comparative description of the public law of different European countries, he deplored the non-execution of the 1698 and 1700 partition treaties: 'Plus heureuse mille fois la France, si le feu Roi avoit pû faire exécuter le Traité de partage!' 129 If the War of the Spanish Succession had had a practical utility, it was mainly for the British, who obtained Gibraltar, the Hudson Bay, Newfoundland, parts of Acadia and Saint-Christopher. As for the law of nations, the war proved one single point, namely: 'Si cet exemple, qu'ont donné les Traités d'Utrecht, de Bade, & de Rastadt, prouve quelque chose, c'est que les renonciations à la future succession d'un Etat Souverain sont bonnes.' 130

(3) Louis XIV, a Threat to the Whole of Europe For Vattel, there was no doubt that Louis XIV had aimed to totally dominate Europe. The more sophisticated argumentations of Louis XIV's military advisers Chamlay (1650-1719) and Vauban (1633-1707), who preferred to fight the inevitable war with the strategic advantage of beginning outside France's border, 131 did not count for the Neuchatelian lawyer. The 'proofs of arrogance and limitless ambition' already shown in the past were a sufficient pretext for Vattel to arm a Europe-wide coalition against France. 132 The whole continent would have been enslaved by the acceptance of Charles II's will. 133 Clearly a contradiction, if we consider Vattel's point of view expressed above, according to which the Spanish nation was sovereign in designating its new monarch. Vattel's treatment of the outbreak of the War of the Spanish Succession bears the title 'how appearances of danger can give the right to wage war'. Preventive warfare against the potential hegemon was clearly justified in his eyes. Vattel's reasoning on the matter was completely political. The intentions of Louis XIV mattered, not the actual actions undertaken by the French.

Vattel's anti-French sentiment becomes even more apparent when he treated the case of Savoy. A notoriously inconstant ally, duke Victor Amadeus II of Savoy (1666-1732) had a black reputation of betrayal and changing alliances, gearing its policy on eternal interests, rather than transitory contractual agreements. 134 During the Nine Years' War (1688-1697), Savoy started on the allied side, but prematurely quit the alliance against Louis XIV, ultimately obtaining the wedding of both Louis XIV's eldest grandsons to Savoyard princesses (1697, 1701). The War of the Spanish Succession started with Savoy in the French camp. Yet, after barely a year of fighting, Victor Amadeus II switched sides once again, attacking the French army in the rear (8 November 1703). 135 Vattel omitted the latter movement, and chose to emphasize Victor Amadeus' switching to Louis XIV during the Nine Years' War, 'under French pressure.' 136 (4) Vattel's Sympathy for the Anti-French Alliance: Fair and Balanced ?

As cruelties of the war (rules of the ius in bello), are concerned, Vattel showed some compassion for the bombardment of Dunkirk in 1694. 137 Damage to the harbor and portuary installations of a notorious corsair basis was the product of military necessity. Nevertheless, the bombardment remained a tragic event, for which he mentioned the compassion of Queen Mary II Stuart (1662-1694), wife of King William III (1650-1702), spin in the web of alliances against Louis XIV. 138 Vattel used William III's capture of Marshal Boufflers after the siege of Namur in 1695 as an example of the exceptio non adimpleti contractus. William could violate existing agreements with the French, since they had infringed on the capitulation agreements for Dixmude and Deinze, two cities in the County of Flanders. 139 Louis' support for the Old Pretender (1688-1766), the son of the chased Catholic King of England and Scotland, James II/James VII (1633-1701), was treated politically as well. Louis' recognition of the rights of James 'III' as his father's son, was dismissed by Vattel as a mere 'insult' to the British nation. 140 Réal, however, took up the defence of the French point of view. Louis had granted asylum to James II. At the Treaty of Rijswijk (20 September 1697), 141 Louis had undertaken the obligation not to disturb William III in his possession of the Kingdom of England. James' son was recognised in order not to let him drop out of the Society of Princes. Acknowledging a mere title to James 'III' could not be an issue in the mutual Anglo-French relationship. James 'III' could and would not receive any more assistance in recovering his domains across the Channel than his father. Moreover, how could Louis act as a judge between William III and James 'III', 'en lui refusant un titre que sa naissance lui donnoit' ? 142

Conclusion

Finally, there is a point where Vattel and Réal join: the legality of alienations contracted by the French sovereign. Réal argued it was a mistake to reason from the civil-law analogy of a usufruct exercised by the monarch on his territories and his ensuing incapability to alienate. This would make the whole network of peace treaties crumble. The theory of the lois fondamentales pushed to its extremities, caused absurd consequences, slavishly copied in French doctrine. If a King could not create obligations for his successor, Europe would be in a state of perpetual war: 143 Vattel came to a similar point of view, but from a bottom-up perspective: 'les Nations, ou Etats, sont des Corps Politiques, des sociétés d'hommes'. 144 Alienations consented to by the corpus of the nation could be deemed void. 145 However, this opened Pandora's box ! In the light of d'Aguesseau's and Joly de Fleury's remarks at the registration of Louis XIV's lettres patentes in 1713, it could be argued that the Parliament of Paris had only registered the treaty, but had opposed itself to Philip V's renunciation. However, the Parliament was a court of justice, and not an assembly representing the Nation or its Estates, as the Riksdag in Sweden, an example cited by Vattel. 146 The absolute limit on obligations undertaken by a sovereign was in both cases the primary obligation of man under the law of nature: self-preservation. Vattel 147 as well as Réal rejected a supranational integration of international law and described the law of nations of a society, not of a community. Bien étonnés de se retrouver ensemble ? Rather not. Although the common premise was sovereignty, their treatment of the Spanish Succession (albeit more implicit with Vattel than with the more erudite Réal de Curban) shows that the choice for the 'Société des Princes' or a patriotic Republic as touchstone for the validity of international intercourse 148 had more links with political history than with abstract reasoning.

In conclusion, the present selective analysis of two classics of eighteenth century international law doctrine has shown that the War of the Spanish Succession was far from over for either Vattel or Réal. Depending on the mission of international scholarship, their methods can be judged differently. Either legal scholars serve to codify the practice, with the most impartial care for accuracy and transparency. In that case, Réal can be said to have been conscious of multiple opinions and, thus, of the need to produce arguments to justify his affirmations. Or, conversely, if scholars feel entrusted with a prescriptive or normative mission, their subjectivity is less problematic. Vattel was not unaware of the pressing needs of politics as a shrewd defender of Neuchâtel. He drew a caricature of French policy during the 'Grand Siècle', although he could have consulted a considerable amount of readily available edited primary sources. If this omission had strengthened the systematic coherence of his work, implicit partiality not have drawn our attention. Yet, Vattel's extraordinary success was more due to his ad hoc and contradictory compilation of arguments in all possible directions. 149

II. Printed sources

A general collection of treaties, declarations of war, manifestos and other public papers relating to peace and war among the potentates of Europe from 1648 to the present time (London 1732). 144 Vattel, B. I, Preliminaries, §1. 145 Vattel,B. IV,Ch. II,§11. 146 Ibid., §10. 147 'Les devoirs envers soi-meme l'emportant incontestablement sur les devoirs envers autrui, une Nation se doit premièrement & préferablement à elle-méme tout ce qu'elle peut faire pour son bonheur & pour sa perfection.' (Vattel, B. I, Preliminaries, §14) ; 'l'intérêt seul agit puissamment sur le coeur des hommes. Inséparable de l'amour propre, il est le principe & l'origine de toutes nos actions' (Réal, B. V, Preface, II, 4). 148 'providing republican thought with a territorial architecture' (Hunter, 'Kant and Vattel', 493). 149 Chetail, 'Vattel and the American Dream'.

B

  . Vattel: A Pamphlet Against the Sun King ? 'Je suis né dans un pais, dont la Liberté est l'ame, le trésor & la Loi fondamentale' Vattel, Le droit des gens ou principes de la loi naturelle, preface (1) Salus populi suprema lex ! The Bottom-Up Construction of Sovereignty

  Dr. Frederik Dhondt (UGent), Postdoctoral Research Fellow of the Research Foundation Flanders (FWO) -Visiting Fellow, Graduate Institute of International and Development Studies (Geneva), Frederik.Dhondt@UGent.be. Sources I. Manuscript sources Archives Diplomatiques, Minsitère des Affaires Étrangères et Européennes (France), Correspondance Politique, Angleterre, 220 ; Angleterre (supplément), 7. National Archives (UK), State Papers Foreign, 78 (France), 165, 174.

  38 was more favourably received. Dietrich Heinrich Ludwig von Ompteda (1746-1803), however, had AlexanderOrakhelashvili (ed.), Research Handbook on the Theory and History of International Law (Cheltenham 2011), 23-60. Paris 1691), XII, §62.: 'ils sont plagiaires, traducteurs, compilateurs; ils ne pensent point, ils disent ce que les autres ont pensé; et, comme le choix des pensées est invention, ils l'ont mauvais, peu juste et qui les détermine plutôt à rapporter beaucoup de choses que d'excellentes choses; ils n'ont rien d'original et qui soit à eux.' 36 Fanny Siam, "Une soumission éclairée n'en est que plus prompte et plus sincère" : souveraineté et bonheur public chez le jurisconsulte Gaspard de Réal de Curban (1682-1752) (diss. lic.) (Genève 2000), 11-15. In spite of Réal's condemnation by the philosophes, he received a Spanish translation of his work by Don Mariano Joseph Sala, La Ciencia del Gobierno, Obra de Moral, de Derecho, y de Politica, que comprehende los principios del Mando, y de la Obediencia, en qué se reducen todas las materias de Gobierno (Madrid 1775), as well as a German, Die Staatskunst oder vollständige und gründliche Anleitung zu Bildung kluger Regenten, geschickter Staatsmänner und rechtschaffener Bürger (transl. Johann Philipp Schulin) (Leizpig 1766), 1076 p. The Jesuit journal Journal de Trévoux extensively reported on each volume published, lauding his 'érudition immense, génie ferme, critique sûre, logique saine, précision également méthodique et lumineuse'

30 Jean Rousset de Missy, Les intérêts présens des puissances de l'Europe, Fondez sur les Traitez conclus depuis la Paix d'Utrecht inclusivement, & sur les Preuves de leurs Prétentions particulieres (La Haye 1733), I, 59. 31 Johannes Burkhardt, 'Geschichte als Argument in der Habsburgisch-Französischen Diplomatie', in: Sven Externbrink (ed.), Formen internationaler Beziehungen in der Frühen Neuzeit; Frankreich und das Alte Reich im europäischen Staatensystem: Festschrift für Klaus Malettke zum 65. Geburtstag, (Berlin 2001), 191-217. 32 Voltaire, Histoire du siècle de Louis XIV (La Haye 1752); Voltaire, Essay sur l'Histoire générale, et sur les moeurs et l'esprit des nations, depuis Charlemagne jusqu'a nos jours . Nouvelle edition, revuë, corrigée & considérablement augmentée. (Genève 1761). 33 Chantal Grell, L'histoire entre érudition et philosophie : étude sur la connaissance historique à l'âge des Lumières (Paris 1993), 28. 34 'une science hérissée, souvent ridicule, et quelquefois barbare' (Jean le Rond d'Alembert, Discours préliminaire de l'Encyclopédie, Paris 1871 [1763], 76. 35 Jean de La Bruyère, Les Caractères de Théophraste, traduits du grec, ou les Caractères avec les moeurs de ce siècle. (

  Bouclier d'estat et de justice contre le dessein manifestement découvert de la monarchie universelle, sous le vain prétexte des prétentions de la reyne de France ((S. l.) 1667); Markus Baumanns, Das publizistische Werk des kaiserlichen Diplomaten Franz Paul Freiherr von Lisola (1613-1674) : ein Beitrag zum Verhältnis von Absolutistischem Staat, Öffentlichkeit und Mächtepolitik in der frühen Neuzeit (Berlin 1994); Delphine Montariol, Les droits de la reine. La guerre juridique de dévolution (1667-1674) (diss. doc). (Toulouse 2005); Antoine Bilain, Traité des droits de la reine très-chrétienne sur divers États de la monarchie d'Espagne (Paris 1667) ; Philippe Le Bailly, Louis XIV et la Flandre, problèmes économiques,

Vattel, B. II, Ch. XV, §223. 55 Ibid., Ch. XV, §225. 56 Ibid., Ch. XVIII, §335. 57 Mignet, Négociations, 64-89. 58 François-Paul de Lisola, prétextes juridiques (diss. doc.) (Paris 1970) ; Pierre Stockmans, Tractatus de jure devolutionis (Bruxellis 1667). 59 Karl-Heinz Lingens, 'Kongresse im Spektrum der Friedenswahrenden Instrumente des Völkerrechts', in: Heinz Duchhardt (ed.), Zwischenstaatliche Friedenswahrung in Mittelalter und früher Neuzeit (Köln 1991), 205-226; Heinz Duchhardt, Gleichgewicht der Kräfte, Convenance, europäisches Konzert. Friedenskongresse u. Friedensschlüsse vom Zeitalter Ludwigs XIV. bis zum Wiener Kongress (Darmstadt 1976). 60 Vattel, B. II, Ch. XVIII, §330.

  Jean du Mont de Carels-kroon's Corps Universel Diplomatique du Droit des Gens 66 and its complementary volumes by Jean Rousset de Missy 67 were standard works. Whereas Grotius mainly quoted examples from Antiquity, Réal or Vattel had no similar heuristic problems: published documents, legal as well as political, were abundant. Both men lived in a different era 61 Treaty of Peace between Charles VI and Louis XV, Vienna, 3 October 1735, Rousset, Supplément au CUD, II, nr. CXCVII, 546-548. Recueil des guerres et traités de paix, de trêve, d'alliance d'entre les rois de France et d'Angleterre depuis Philippe Ier, roi de France, jusqu'à Henri II (Paris 1588), or the Germans Goldast, Impp., regum et electorum S.R.I. statuta et rescripta a Carolo M. ad Carolo V, et a Carolo V ad Rudolphum II (Frankfurt, 1607) and Hortleder, Ursachen des Schmalkaldischen Krieges (Jena 1617). Rousset made his own adaptation of the Theatrum Europeum-collection, which started in 1617 (Frankfurt) and ran up to 21 versions (1738) (Theatrum Europaeum Oder Außführliche und Warhafftige Beschreibung aller und jeder denckwürdiger Geschichten (Frankfurt 1617-1738). Contemporary publications, such as those of Zink (Ruhe des jetzt lebenden Europa Oder Die neueste und merkwürdigste Europaeische Friedens-Handlungen, Commercien -Tractate, Neutralitäts-Acten, Waffen-Stillständte / Confoederationen, Allianzen, Gvarantien, nebst andern publiqven Sanctionen und Uhrkunden, Coburg 1727) or Johann Christian Lunig (Codex Germaniae Diplomaticus, Leipzig, 1732-1733; Das Teutsche Reichs-Archiv, Leipzig 1710-1723) did not cover more than Du Mont and Rousset's collection, nor did the English A general collection of treaties, declarations of war, manifestos and other public papers relating to peace and war among the potentates of Europe from 1648 to the present time (London 1732) or Rymer's historically oriented volumes. It should be noted, that his approach of ancient history already consisted a step further than that of his predecessors (Ernest Nys, Le droit de la guerre et les précurseurs de Grotius (Bruxelles 1882), 155; Stephen C. Neff, Justice Among Nations. A History of International Law (Cambridge (Mass.) 2014) 190). 66 Jean Du Mont de Carels-kroon, Nouveau recueil de traités d'alliance, de trêve, de paix, de garantie et de commerce faits et conclus entre les rois, princes et Etats souverains de l'Europe, depuis la paix de Munster juesqu'à l'an 1709 (Amsterdam 1710); Idem, Corps universel diplomatique du droit des gens (La Haye 1731); F. De Martens, "Recherches sur la vie et les écrits de Jean du Mont Baron de Carelscroon, redacteur du Corps universel diplomatique du droit des gens", in: F. De Martens (ed.), Supplément au recueil des principaux traités d'alliance, de paix, de trêve, de neutralité, de commerce, de limites, d'échange etc. (Göttingen 1802), lxiv-xciv ; Jean Dumont de Carels-Kroon, La vérité du fait, du droit, et de l'intérêt de tout ce qui concerne le commerce des Indes, etabli aux Païs Bas Autrichiens par octroi de sa Majesté Impér. et Catholique (s.l. 1726); Idem and Jan Van Huchtenburg, Batailles gagnées par le serenissime prince Fr. Eugene de Savoye sur les ennemis de la foi, et sur ceux de l'Empereur, & de l'Empire, en Hongrie, en Italie, en Allemagne & aux Pais-Bas (A La Haye 1725).

62

Vattel, B. II, Ch. XVI, §238.

63

Ibid., Ch. XII, § 165.

64

Solange Rameix, Justifier la guerre : Censure et propagande dans l'Europe du XVII e siècle (France-Angleterre) (Rennes 2014). 65 Martens, preface, reprint in CTS I, x, pointing to collections by Jean Tillet (greffier at the Parliament of Paris), 67 Jean Rousset de Missy, Supplément au Corps universel diplomatique du droit des gens, contenant un recueil des Traitez d'alliance de paix, de trève, de neutralité (Amsterdam 1739); Idem, Les intérêts présens des puissances de l'Europe, Fondez sur les Traitez conclus depuis la Paix d'Utrecht inclusivement, & sur les Preuves de leurs Prétentions particulieres; Idem, Mémoires sur le rang et la préséance entre les souverains de l'Europe et entre leurs ministres représentans suivant leurs différens Caractères. Pour servir de supplement à l'ambassadeur et ses fonctions de Mr. de Wicquefort (Amsterdam 1746); Idem, Recueil historique d'actes, négotiations, mémoires et traitez, depuis la Paix d'Utrecht (La Haye 1728).

  [Philip V], to instate Charles III as King of Spain, Genoa, 20 June 1705. 70 Treaty of Peace between Philip V and Queen Anne, Utrecht, 2 July 1713, CUD VIII/1, nr. CLXIV, 393-400. 71 Convention between the belligerent parties, mediated by Queen Anne, for the Evacuation of Catalonia and for an armistice in Italy, Utrecht, 14 March 1713, CUD, VIII/1, nr. CXLVII, 327-330; Agreements for the Execution of the Treaty for the Evacuation of Catalonia between Charles VI, Queen Anne and Louis XIV, El Hospitalet, 22 June 1713, 28 CTS 233. Espagne: des espérances de 1705 à la perte des libertés de 1714', Revue d'histoire diplomatique CXXI (2007), 231-248. possible claims, pretentions, mortgages, or literally stipulate he could only transfer the rights he actually held (nemo plus transferre potest quam ipse haberet): 74

72

Treaty of Peace between Charles VI and Philip V, Vienna, 30 April 1725, CUD VIII/2, nr. XXXVI, 106-113.

73 Joaquim Albareda i Salvadó, 'La Catalogne et Philippe V d'Espagne dans la guerre de Succession d'

  James Stanhope to GuillaumeDubois, Hanover, 22 August 1719, NA, SP, 78, 165, f. 51r°. James Stanhope (1673-1721), Whig politician, fought as commander in Spain during the War of the Spanish Succession and occupied various ministerial and diplomatic charges. BasilWilliams, Stanhope. A Study in Eighteenth-Century War and Diplomacy (Oxford 1932). Guillaume Cardinal Dubois (1656-1723), preceptor of Philip of Orléans, French Regent. Secretary of State for Foreign Affairs (1718), Prime Minister (1723). Frederik Dhondt, 'Kardinaal Dubois door Hyacinthe Rigaud (1723). Een insider's view op een bibliotheek van de macht in de Grand Siècle', Pro Memorie. Bijdragen tot de rechtsgeschiedenis der Nederlanden XVI (2014),188-198. 87 Treaty of Peace between Philip V and Queen Anne, Utrecht, 11 April 1713, CUD VIII/1, nr. CLXIV, 396: 'The Catholic King concedes to the Catalans, for the grace of Her Brittanick Majesty their old privileges […], the full possession of all of their goods and honours, but even all of the privileges enjoyed until this time by the inhabitants of Castile, the most favoured of all of his subjects.'88 Accession by Philip V to the Treaty of the Quadruple Alliance, The Hague, 17 February 1720, CUD VIII/2, nr. XI,26-27. 89 Treaty of Alliance between Charles VI, Louis XV and George I, London, 2 August 1718, CUD, VIII/2, nr. CCII, 531-541.90 Stair to James Stanhope, Paris, 12 June 1718, SP, 78, 161, f. 311v°. However, during the War of the Spanish Succession, both the Regent and Stanhope had fought in the military campaigns. Late in 1708, the latter tried to seduce the former into leaving the Spanish alliance in exchange for the creation of an independent kingdom in the North-East of Spain, comprising Valencia, Aragon and Catalonia (Jean-Christian Petitfils, Le Régent (Paris 1986), 152). Alexander Hume Campbell, second earl of Marchmont (1675-1740) studied civil law in Utrecht, envoy, then extraordinary ambassador inCopenhagen (1716-1721). Charles Baron Whitworth (1675-1725), studies at Westminster and Trinity

91

Frederik Dhondt, 'La culture juridique pratique au Congrès de Cambrai (1722-1725)', Revue d'histoire diplomatique CXXVII (2013), 271-292.

92

Polwarth and Whitworth to Newcastle, Cambrai, 20 May 1724, NA, SP,

78, 174, f. 20r°-v°.

  Réal, B. V, Ch. II, S. IX, V, 445 95 Ibid., Ch. I, S. XVI, V, 321 96 Ibid., Ch. II, S. IX, V, 442. 97 Ibid., Ch. II, S. IX, V, 444. First Mucius Scaevola, then Fabricius, Augustus and Tiberius. Réal omitted the Middle Ages, and continued with Charles V, who refused to have the Turk Barbarossa assassinated. Stanhope, 350; Emile Bourgeois, La Diplomatie secrète au XVIII e siècle (Paris 1910), III, 278. See also Frederik Dhondt, Balance of Power and Norm Hierarchy. Franco-British Diplomacy After the Peace of Utrecht (

98

Ibid., Ch. III, S. 1, VII, 562. 99 Ibid., 561. 100 Ibid., 563. Letter of George I to Philip V, London, 1 June 1721, AMAE, CP, Angleterre (suppl.), 7, f. 14r°.

101 Linking Gibraltar to the obtention of a compensation in the West Indies (Florida, Hispaniola). Basil Williams,

Treaty of Alliance between Emperor Leopold I, William III and the States-General, The Hague, 7 September 1701, CUD, VIII/1, nr. XIII, 89-91.