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Samuel of Bulgaria

Samuel (also Samoil or Samuil; Самуил, ; Самоил/Самуил, ; Old Church Slavonic: Самоилъ; died 6 October 1014) was the Tsar (Emperor) of the First Bulgarian Empire from 997 to 6 October 1014. From 977 to 997, he was a general under Roman I of Bulgaria, the second surviving son of Emperor Peter I of Bulgaria, and co-ruled with him, as Roman bestowed upon him the command of the army and the effective royal authority. As Samuel struggled to preserve his country's independence from the Byzantine Empire, his rule was characterized by constant warfare against the Byzantines and their equally ambitious ruler Basil II.

In his early years, Samuel managed to inflict several major defeats on the Byzantines and to launch offensive campaigns into their territory. In the late 10th century, the Bulgarian armies conquered the Serb principality of Duklja and led campaigns against the Kingdoms of Croatia and Hungary. But from 1001, he was forced mainly to defend the Empire against the superior Byzantine armies. Samuel died of a heart attack on 6 October 1014, two months after the catastrophic battle of Kleidion. His successors failed to organize a resistance, and in 1018, four years after Samuel's death, the country capitulated, ending the five decades-long Byzantine–Bulgarian conflict.

Samuel was considered "invincible in power and unsurpassable in strength". Similar comments were made even in Constantinople, where John Kyriotes penned a poem offering a punning comparison between the Bulgarian Emperor and Halley's comet, which appeared in 989. During Samuel's reign, Bulgaria gained control of most of the Balkans (with the notable exception of Thrace) as far as southern Greece. He moved the capital from Skopje to Ohrid,  which had been the cultural and military centre of southwestern Bulgaria since Boris I's rule, and made the city the seat of the Bulgarian Patriarchate. Because of this, his realm is sometimes called the Western Bulgarian Empire. Samuel's energetic reign restored Bulgarian might on the Balkans, even though the Empire was disestablished after his death.

The Cometopuli
Samuel was the fourth and youngest son of count Nicholas, a Bulgarian noble, who might have been the count of Sredets district (modern-day Sofia), although other sources suggest that he was a regional count of Prespa district in the region of Macedonia. His mother was Rhipsime of Armenia. The actual name of the dynasty is not known. Cometopuli is the nickname used by Byzantine historians which is translated as "sons of the count". The Cometopuli rose to power out of the disorder that occurred in the Bulgarian Empire from 966 to 971.

Rus' invasion and the deposition of Boris II
During the reign of Emperor Peter I, Bulgaria prospered in a long-lasting peace with Byzantium. This was secured by the marriage of Peter with the Byzantine princess Maria Lakapina, granddaughter of Byzantine Emperor Romanos I Lekapenos. However, after Maria's death in 963, the truce had been shaken and it was at this time or later that Peter I sent his sons Boris and Roman to Constantinople as honorary hostages, to honor the new terms of the peace treaty. During these years the Byzantines and Bulgarians had entangled themselves in a war with Kievan Rus' Prince Sviatoslav, who invaded Bulgaria several times. After a defeat from Sviatoslav, Peter I suffered a stroke and abdicated his throne in 969 (he died the next year). Boris was allowed back to Bulgaria to take his father's throne, restore order and oppose Sviatoslav, but had little success. This was allegedly used by Nicholas and his sons, who were contemplating a revolt in 969.

The Rus' invaded Byzantine Thrace in 970, but suffered a defeat in the Battle of Arcadiopolis. The new Byzantine Emperor John Tzimiskes used this to his advantage. He quickly invaded Bulgaria the following year, defeated the Rus, and conquered the Bulgarian capital Preslav. Boris II of Bulgaria was ritually divested of his imperial insignia in a public ceremony in Constantinople and he and his brother Roman of Bulgaria remained in captivity. Although the ceremony in 971 had been intended as a symbolic termination of the Bulgarian Empire, the Byzantines were unable to assert their control over the western provinces of Bulgaria. Count Nicholas, Samuel's father, who had close ties to the royal court in Preslav, died in 970. In the same year "the sons of the count" (the Cometopuli) David, Moses, Aaron and Samuel rebelled. The series of events are not clear due to contradicting sources, but it is sure that after 971 Samuel and his brothers were the de facto rulers of the western Bulgarian lands.

In 973, the Cometopuli (described by Thietmar of Merseburg simply as the Bulgarians) sent envoys to the Holy Roman Emperor Otto I in Quedlinburg in an attempt to secure the protection of their lands. The brothers ruled together in a tetrarchy. David ruled the southernmost regions and led the defense of one of the most dangerous border areas, around Thessaloniki and Thessaly. The centres of his possessions were Prespa and Kastoria. Moses ruled from Strumitsa, which would be an outpost for attacks on the Aegean coast and Serres. Aaron ruled from Sredets, and was to defend the main road from Adrianople to Belgrade, and to attack Thrace. Samuel ruled northwestern Bulgaria from the strong fortress of Vidin. He was also to organize the liberation of the conquered areas to the east, including the old capital Preslav. Some records suggest that David played a major role in this tumultuous period of Bulgarian history.

War with Byzantium
After John I Tzimiskes died on 11 January 976, the Cometopuli launched an assault along the whole border. Within a few weeks, however, David was killed by Vlach vagrants and Moses was fatally injured by a stone during the siege of Serres. The brothers' actions to the south detained many Byzantine troops and eased Samuel's liberation of northeastern Bulgaria. A local Bulgarian uprising broke there, led by two boyars – Petar and Boyan, who became allies of the Cometopuli and submitted to their rule. The Byzantine army was defeated and retreated to Crimea. Any Bulgarian nobles and officials who had not opposed the Byzantine conquest of the region were executed, and the war continued north of the Danube until the enemy was scattered and Bulgarian rule was restored.

After suffering these defeats in the Balkans, the Byzantine Empire descended into civil war. The commander of the Asian army, Bardas Scleros, rebelled in Asia Minor and sent troops under his son Romanus in Thrace to besiege Constantinople. The new Emperor Basil II did not have enough manpower to fight both the Bulgarians and the rebels and resorted to treason, conspiracy and complicated diplomatic plots. Basil II made many promises to the Bulgarians and Scleros to divert them from allying against him. Aaron, the eldest living Cometopulus, was tempted by an alliance with the Byzantines and the opportunity to seize power in Bulgaria for himself. He held land in Thrace, a region potentially subject to the Byzantine threat. Basil reached an agreement with Aaron, who asked to marry Basil's sister to seal it. Basil instead sent the wife of one of his officials with the bishop of Sebaste. However, the deceit was uncovered and the bishop was killed. Nonetheless, negotiations proceeded and concluded in a peace agreement. The historian Scylitzes wrote that Aaron wanted sole power and "sympathized with the Romans". Samuel learned of the conspiracy and the clash between the two brothers was inevitable. The quarrel broke out in the vicinity of Dupnitsa on 14 June 976 and ended with the annihilation of Aaron's family. Only his son, Ivan Vladislav, survived because Samuel's son Gavril Radomir pleaded on his behalf. From that moment on, practically all power and authority in the state were held by Samuel and the danger of an internal conflict was eliminated.

However, another theory suggests that Aaron participated in the battle of the Gates of Trajan which took place ten years later. According to that theory Aaron was killed on 14 June 987 or 988.

Co-rule with Roman
After the Byzantine plan to use Aaron to cause instability in Bulgaria failed, they tried to encourage the rightful heirs to the throne, Boris II and Roman, to oppose Samuel. Basil II hoped that they would win the support of the nobles and isolate Samuel or perhaps even start a Bulgarian civil war. Boris and Roman were sent back in 977 but while they were passing through a forest near the border, Boris was killed by Bulgarian guards who were misled by his Byzantine clothing. Roman, who was walking some distance behind, managed to identify himself to the guards.

Roman was taken to Vidin, where he was proclaimed Emperor of Bulgaria. Samuel became his first lieutenant and general and together they gathered an army and fought the Byzantines. During his captivity, Roman had been castrated on the orders of John I Tzimiskes so that he would not have heirs. Thus Samuel was certain to eventually succeed Roman. The new emperor entrusted Samuel with the state administration and became occupied with church and religious affairs.

As the main effort of Basil II was concentrated against the rebel Skleros, Samuel's armies attacked the European possessions of the Byzantine Empire. Samuel invaded not only Thrace and the area of Thessaloniki, but also Thessaly, Hellas and the Peloponnese. Many Byzantine fortresses fell to the Bulgarians. Samuel wanted to seize the important fortress of Larissa, which controlled the key routes in Thessaly, and from 977 to 983 the town was blockaded. After starvation forced the Byzantines to surrender, the population was deported to the interior of Bulgaria and the males were forced to enlist in the Bulgarian army. Although Basil II sent forces to the region, they were defeated. With this victory, Bulgaria had gained influence over most of the southwestern Balkans, although it did not occupy some of these territories. From Larissa, Samuel took the relics of Saint Achilleios, which were laid in a specially built church of the same name on an island in Lake Prespa.

The Bulgarian successes in the west raised fears in Constantinople, and after serious preparations, Basil II launched a campaign into the very centre of the Bulgarian Empire to distract Samuel from southern Greece. The Byzantine army passed through the mountains around Ihtiman and besieged Sredets in 986. The Byzantines assaulted the city for 20 days, but their attacks proved fruitless and costly: the Bulgarians came out of the city several times, killed many enemy soldiers and captured draught animals and horses. Eventually, the Bulgarian troops burned the siege equipment of the Byzantine army, forcing Basil II to withdraw to Thrace, but on 17 August 986, while passing through the mountains, the Byzantine army was ambushed and routed at the Trajan's Gates Pass. This was a significant blow for Basil, who was one of the few to return to Constantinople; his personal treasure was captured by the victors.

After the defeat, the rebellion of Bardas Phocas diverted the efforts of the Byzantine Empire into another civil war. Samuel seized the opportunity and began to exert pressure on Thessaloniki. Basil II sent a large army to the town and appointed a new governor, Gregorios Taronites, but he was powerless to stop the Bulgarian advance. By 989, the Bulgarian troops had penetrated deep into Byzantine territory, and seized many fortresses, including such important cities as Veria and Servia. In the south, the Bulgarians marched throughout Epirus and in the west they seized the area of modern Durrës (medieval Dyrrhachium or Drach) on the Adriatic Sea.

In 989, Phocas was killed and his followers surrendered, and the following year Basil II reached an agreement with Skleros. The Byzantines focused their attention on Bulgaria, and counter-attacked in 991. The Bulgarian army was defeated and Roman was captured while Samuel managed to escape. The Byzantines conquered some areas; in 995, however, the Arabs invaded Asia Minor and Basil II was forced to move many of his troops to combat this new threat. Samuel quickly regained the lost lands and advanced south. In 996, he defeated the Byzantines in the battle of Thessaloniki. During the battle, Thessaloniki's governor, Gregorios, perished and his son Ashot was captured. Elated by this success, the Bulgarians continued south. They marched through Thessaly, overcame the defensive wall at Thermopylae and entered the Peloponnese, devastating everything on their way.

As a response, a Byzantine army under Nikephorus Uranos was sent after the Bulgarians, who returned north to meet it. The two armies met near the flooded river of Spercheios. The Byzantines found a place to ford, and on the night of 19 July 996 they surprised the unprepared Bulgarian army and routed it in the battle of Spercheios. Samuel's arm was wounded and he barely escaped captivity; he and his son allegedly feigned death. After nightfall they headed for Bulgaria and walked 400 km home. Research of Samuel's grave suggests that the bone in his arm healed at an angle of 140° but remained crippled.

Emperor
In 997, Roman died in captivity in Constantinople, ending the line of rulers started by Krum. Because of the war with Byzantium, it was dangerous to leave the throne vacant for long, and Samuel was chosen as the new Emperor of Bulgaria because he had the closest relations to the deceased emperor and was Roman's long-standing military commander. The presbyter of Duklja also marked the event: "By that time among the Bulgarian people rose one Samuel, who proclaimed himself emperor. He led a long war against the Byzantines and expelled them from the whole territory of Bulgaria, so that the Byzantines did not dare to approach it".

Constantinople would not recognize the new emperor, as for the Byzantines Boris II's abdication symbolized the official end of Bulgaria and Samuel was considered a mere rebel. Instead Samuel sought recognition from the Pope, which would be a serious blow to the position of the Byzantines in the Balkans and would weaken the influence of the Patriarch of Constantinople, thereby benefiting both the See of Rome and Bulgaria. Samuel possibly received his imperial crown from Pope Gregory V.

War against Serbs and Croats
In 998, Samuel launched a major campaign against the Duklja to prevent an alliance between Prince Jovan Vladimir and the Byzantines. When the Bulgarian troops reached Duklja, the Serbian prince and his people withdrew to the mountains. Samuel left part of the army at the foot of the mountains and led the remaining soldiers to besiege the coastal fortress of Ulcinj. In an effort to prevent bloodshed, he asked Jovan Vladimir to surrender. After the prince refused, some Serb nobles offered their services to the Bulgarians and, when it became clear that further resistance was fruitless, the Serbs surrendered. Jovan Vladimir was exiled to Samuel's palaces in Prespa.

The Bulgarian troops proceeded to pass through Dalmatia, taking control of Kotor and journeying to Dubrovnik. Although they failed to take Dubrovnik, they devastated the surrounding villages. The Bulgarian army then attacked Croatia in support of the rebel princes Krešimir III and Gojslav and advanced northwest as far as Split, Trogir and Zadar, then northeast through Bosnia and Raška and returned to Bulgaria. This Croato-Bulgarian War allowed Samuel to install vassal monarchs in Croatia.

Samuel's relative Kosara fell in love with the captive Jovan Vladimir. The couple married after gaining Samuel's approval, and Jovan returned to his lands as a Bulgarian official along with his uncle Dragomir, whom Samuel trusted. Meanwhile, Princess Miroslava fell in love with the Byzantine noble captive Ashot, son of Gregorios Taronites, the dead governor of Thessaloniki, and threatened to commit suicide if she was not allowed to marry him. Samuel conceded and appointed Ashot governor of Dyrrhachium. Samuel also sealed an alliance with the Magyars when his eldest son and heir, Gavril Radomir, married the daughter of the Hungarian Grand Prince Géza.

Advance of the Byzantines
The beginning of the new millennium saw a turn in the course of Byzantine-Bulgarian warfare. Basil II had amassed an army larger and stronger than that of the Bulgarians: determined to definitively conquer Bulgaria, he moved much of the battle-seasoned military forces from the eastern campaigns against the Arabs to the Balkans and Samuel was forced to defend rather than attack.

In 1001, Basil II sent a large army under the patrician Theodorokanos and Nikephoros Xiphias to the north of the Balkan Mountains to seize the main Bulgarian fortresses in the area. The Byzantine troops recaptured Preslav and Pliska, putting north-eastern Bulgaria once again under Byzantine rule. The following year, they struck in the opposite direction, marching through Thessaloniki to tear off Thessaly and the southernmost parts of the Bulgarian Empire. Although the Bulgarian commander of the fortress of Veroia, Dobromir, was married to one of Samuel's nieces, he voluntarily surrendered the fort and joined the Byzantines. The Byzantines also captured the fortress of Kolidron without a fight, but its commander Dimitar Tihon managed to retreat with his soldiers and join Samuel. The next town, Servia, did not fall so easily; its governor Nikulitsa organized the defenders well. They fought until the Byzantines penetrated the walls and forced them to surrender. Nikulitsa was taken to Constantinople and given the high court title of patrician, but he soon escaped and rejoined the Bulgarians. He attempted to retake Servia, but the siege was unsuccessful and he was captured again and imprisoned.

Meanwhile, Basil II's campaign reconquered many towns in Thessaly. He forced the Bulgarian population of the conquered areas to resettle in the Voleron area between the Mesta and Maritsa rivers. Edessa resisted for weeks but was conquered following a long siege. The population was moved to Voleron and its governor Dragshan was taken to Thessaloniki, where he was betrothed to the daughter of a local noble. Unwilling to be married to an enemy, Dragshan three times tried to flee to Bulgaria and was eventually executed.

War with Hungary

The Byzantine–Bulgarian conflict reached its apex in 1003, when Hungary became involved. Since the beginning of the 9th century, the Bulgarian territory had stretched beyond the Carpathian Mountains as far as the Tisza River and the middle Danube. During the reign of Samuel, the governor of these northwestern parts was duke Ahtum, the grandson of duke Glad, who had been defeated by the Hungarians in the 930s. Ahtum commanded a strong army and firmly defended the northwestern borders of the Empire. He also built many churches and monasteries through which he spread Christianity in Transylvania.

Although Gavril Radomir's marriage to the daughter of the Hungarian ruler had established friendly relations between the two strongest states of the Danube area, the relationship deteriorated after Géza's death. The Bulgarians supported Gyula and Koppány as rulers instead of Géza's son Stephen I. As a result of this conflict, the marriage between Gavril Radomir and the Hungarian princess was dissolved. The Hungarians then attacked Ahtum, who had directly backed the pretenders for the Hungarian crown. Stephen I convinced Hanadin, Ahtum's right-hand man, to help in the attack. When the conspiracy was uncovered Hanadin fled and joined the Hungarian forces. At the same time, a strong Byzantine army besieged Vidin, Ahtum's seat. Although many soldiers were required to participate in the defense of the town, Ahtum was occupied with the war to the north. After several months he died in battle when his troops were defeated by the Hungarians. As a result of the war, Bulgarian influence to the northwest of the Danube diminished.

Further Byzantine successes
The Byzantines took advantage of the Bulgarian troubles in the north. In 1003, Basil II led a large army to Vidin, northwestern Bulgaria's most important town. After an eight-month siege, the Byzantines ultimately captured the fortress, allegedly due to betrayal by the local bishop. The commanders of the town had repulsed all previous attempts to break their defence, including the use of Greek fire. While Basil's forces were engaged there, Samuel struck in the opposite direction: on 15 August he attacked Adrianople and plundered the area.

Basil II decided to return to Constantinople afterwards, but, fearing an encounter with the Bulgarian army on the main road to his capital, he used an alternate route. The Byzantines marched south through the Morava valley and reached a key Bulgarian city, Skopje, in 1004. The Bulgarian army was camping on the opposite side of the Vardar River. After finding a ford and crossing the river, Basil II attacked and defeated Samuel's unsuspecting army, using the same tactics employed at Spercheios. The Byzantines continued east and besieged the fortress of Pernik. Its governor, Krakra, was not seduced by Basil's promises of a noble title and wealth, and successfully defended the fortress. The Byzantines withdrew to Thrace after suffering heavy losses.

In the same year, Samuel undertook a march against Thessaloniki. His men ambushed and captured its governor, Ioannes Chaldus, but this success could not compensate for the losses the Bulgarians had suffered in the past four years. The setbacks in the war demoralized some of Samuel's military commanders, especially the captured Byzantine nobles. Samuel's son-in-law Ashot, the governor of Dyrrhachium, made contact with the local Byzantines and the influential John Chryselios, Samuel's father-in-law. Ashot and his wife boarded one of the Byzantine ships that were beleaguering the town and fled to Constantinople. Meanwhile, Chryselios surrendered the city to the Byzantine commander Eustathios Daphnomeles in 1005, securing the title of patrician for his sons.

In 1006–1007, Basil II penetrated deep into the Bulgarian-ruled lands and in 1009 Samuel's forces were defeated at Kreta, east of Thessaloniki. During the next years, Basil launched annual campaigns into Bulgarian territory, devastating everything on his way. Although there was still no decisive battle, it was clear that the end of the Bulgarian resistance was drawing nearer; the evidence was the fierceness of the military engagements and the constant campaigns of both sides which devastated the Bulgarian and Byzantine realms.

Disaster at Kleidion

In 1014, Samuel resolved to stop Basil before he could invade Bulgarian territory. Since the Byzantines usually used the valley of the Strumitsa River for their invasions into Bulgaria, Samuel built a thick wooden wall in the gorges around the village of Klyuch (also Kleidion, "key") to bar the enemy's way.

When Basil II launched his next campaign in the summer of 1014, his army suffered heavy casualties during the assaults on the wall. Meanwhile, Samuel sent forces under his general Nestoritsa to attack Thessaloniki so as to distract Basil's forces away from this campaign. Nestoritsa was defeated near the city by its governor Botaniates, who later joined the main Byzantine army near Klyuch. After several days of continuous attempts to break through the wall, one Byzantine commander, the governor of Plovdiv Nicephorus Xiphias, found a by-pass and, on 29 July, attacked the Bulgarians from the rear. Despite the desperate resistance the Byzantines overwhelmed the Bulgarian army and captured around 14,000 soldiers, according to some sources even 15,000. Basil II immediately sent forces under his favourite commander Theophylactus Botaniates to pursue the surviving Bulgarians, but the Byzantines were defeated in an ambush by Gavril Radomir, who personally killed Botaniates. After the Battle of Kleidion, on the order of Basil II the captured Bulgarian soldiers were blinded; one of every 100 men was left one-eyed so as to lead the rest home. The blinded soldiers were sent back to Samuel who reportedly had a heart attack upon seeing them. He died two days later, on 6 October 1014. This savagery gave the Byzantine Emperor his byname Boulgaroktonos ("Bulgar-slayer" in Βουλγαροκτόνος). Some historians theorize it was the death of his favourite commander that infuriated Basil II to blind the captured soldiers.

The battle of Kleidion had major political consequences. Although Samuel's son and successor, Gavril Radomir, was a talented military leader, he was murdered by his cousin Ivan Vladislav, who, ironically, owed his life to him. Unable to restore the Bulgarian Empire's previous power, Ivan Vladislav himself was killed while attacking Dyrrhachium. After that, the widowed empress Maria and many Bulgarian governors, including Krakra, surrendered to the Byzantines. Presian, Ivan Vladislav's eldest son, fled with two of his brothers to Mount Tomorr, before they too surrendered. Thus the First Bulgarian Empire came to an end in 1018, only four years after Samuel's death. Most of its territory was incorporated within the new Theme of Bulgaria, with Skopje as its capital.

In the extreme northwest, the duke of Syrmia, Sermon, was the last remnant of the once mighty Empire. He was deceived and killed by the Byzantines in 1019.

Family, grave and legacy
Samuel's wife was called Agatha, and was the daughter of the magnate of Dyrrhachium John Chryselios. Only two of Samuel's and Agatha's children are definitely known by name: Samuel's heir Gavril Radomir and Miroslava. Two further, unnamed daughters, are mentioned after the Bulgarian surrender in 1018, while Samuel is also recorded as having had a bastard son. Another woman, Kosara, who was wedded to Jovan Vladimir of Duklja and was considered by earlier scholarship as Samuel's daughter, is now regarded to have been simply a relative, perhaps a niece of Agatha. Gavril Radomir married twice, to Ilona of Hungary and Irene from Larissa. Miroslava married the captured Byzantine noble Ashot Taronites.

After the fall of Bulgaria, Samuel's descendants assumed important positions in the Byzantine court after they were resettled and given lands in Asia Minor and Armenia. One of his granddaughters, Catherine, became empress of Byzantium. Another (supposed) grandchild, Peter II Delyan, led an attempt to restore the Bulgarian Empire after a major uprising in 1040 – 1041. Two other women of the dynasty became Byzantine empresses, while many nobles served in the army as strategos or became governors of various provinces.

There is another version of Samuel's origin: the 11th-century historian Stepanos Asoghik wrote that Samuel had only one brother, stating they were both Armenians from the district of Derjan, an Armenian land incorporated into the Byzantine Empire. They were sent to fight the Bulgarians in Macedonia but ended up joining them. This version is supported by the historian Nicholas Adontz, who analyzed the events and facts of the century and concluded that Samuel had only one brother, David. Asoghik's version is also supported by the historian Jordan Ivanov; furthermore, only one brother is mentioned on Samuel's Inscription.

The Arab historian Yahya of Antioch claims that the son of Samuel, Gavril, was assassinated by the leader of the Bulgarians, son of Aaron, because Aaron belonged to the race that reigned over Bulgaria. Asoghik and Yahya clearly distinguish the race of Samuel from the one of Aaron or the race of the Cometopuli from the royal race. According to them, Moses and Aaron are not from the family of the Cometopuli. David and Samuel were of Armenian origin and Moses and Aaron were Armenian on their mother's side.

Samuel's grave was found in 1965 by Greek professor Nikolaos Moutsopoulos in the Church of St Achillios on the eponymous island in Lake Prespa. Samuel had built the church for the relics of the saint of the same name. What is thought to have been the coat of arms of the House of Cometopuli, two perched parrots, was embroidered on his funeral garment.

His remains are kept in the Museum of Byzantine Culture in Thessaloniki, but according to a recent agreement, they may be returned to Bulgaria and buried in the SS. Forty Martyrs Church in Veliko Tarnovo, to rest with the remains of Emperors Kaloyan and Michael Shishman.

Samuel's face was reconstructed to restore the appearance of the 70-year-old Bulgarian ruler. According to the reconstruction, he was a sharp-faced man, bald-headed, with a white beard and moustache.

Samuel is among the most renowned Bulgarian rulers. His military struggle with the Byzantine Empire is marked as an epic period of Bulgarian history. The great number of monuments and memorials in Bulgaria and the Republic of Macedonia, such as the ones in Petrich and Ohrid, signify the trail this historical figure has left in the memory of the people. Four Bulgarian villages bear his name, as well as Samuel Point on Livingston Island, Antarctica. Samuel is the main figure in at least three major Bulgarian novels by authors Dimitar Talev, Anton Donchev and Stefan Tsanev and also stars in the Greek novel "At the Times of the Bulgarian-Slayer" by Penelope Delta, who closely follows the narrative flow of events as presented by St. Runciman. He is mentioned in the verse of Ivan Vazov, Pencho Slaveykov, and Atanas Dalchev as well.

Overview
Samuel's empire had its heartlands in the modern region of Macedonia, west and southwest of the city of Ohrid, this earlier cultural center of the First Bulgarian Empire. After the area was taken in 1913 after five centuries Ottoman rule by the Kingdom of Serbia, (later Yugoslavia), that has led to assertions by the nationalist-driven historiography there. Its main agenda was that Samuel's empire was a "Serbian"/"Macedonian Slavic" state, distinct from the Bulgarian Empire. In more recent times the same agenda has been maintained in the Republic of Macedonia, (now North Macedonia).

Practically Serbia did not exist at that time. It became independent under Časlav ca. 930, only to fall ca. 960 under Byzantine and later under Bulgarian rule. In fact that area was taken for the first time by Serbia centuries later, during the 1280s. Moreover, in Samuel's time Macedonia as a geographical term referred to part of the region of modern Thrace. The "Macedonian" emperors of that period were Basil II, called "Bulgar-Slayer", and his Byzantine relatives from the Macedonian dynasty, originating from the territory of today's European Turkey. Most of the modern region of Macedonia was then a Bulgarian province known as Kutmichevitsa. The area was incorporated into the Byzantine Empire in 1018 as a new province called Bulgaria.

The very name of "Macedonia" for the modern region was revived only in the 19th century, after it had nearly disappeared during the five centuries of Ottoman rule. Until the early 20th century and beyond the majority of the Macedonian Slavs who had clear ethnic consciousness believed they were Bulgarians. The Balkan Wars (1912–1913) and World War I (1914–1918) left the area divided mainly between Greece and Serbia (later Yugoslavia), which resulted in significant changes in its ethnic composition. The formerly leading Bulgarian community was reduced either by population exchanges or by change of communities' ethnic identity. The Macedonian Slavs were faced with the policy of forced Serbianisation.

Yugoslav agenda
20th-century Serbian and afterwards the Yugoslav historiography used the location of Samuel's state mainly on the territory of then Yugoslavia, to reject Bulgarian claims on the region. Thus, the Russian-born Yugoslavian historian George Ostrogorsky distinguished Samuel's Empire from the Bulgarian Empire, referring to it as a "Macedonian Empire", although he recognised that Samuel's state was politically and ecclesiastically a direct descendant of the empire of Simeon I of Bulgaria and Peter I of Bulgaria, and it was regarded by Samuel and the Byzantines as being the Bulgarian Empire itself.

Some historians of the same school, such as the Serbian scholar Dragutin Anastasijević, even claimed that Samuel ruled a separate South Slavic, i.e. Serbian Empire in Macedonia, founded as result of an anti-Bulgarian rebellion. The Serbs tried to popularize the Serbian past of that distinct state and its Serbian rulers. The story continued in Communist Yugoslavia, where a separate Macedonian identity was formed and Samuel was depicted as a Macedonian Tsar. After the breakup of Yugoslavia, these outdated theories have been rejected by authoritative Serbian historians from SANU as Srđan Pirivatrić and Tibor Živković. Pirivatrić has stated, that incipient Bulgarian identity was available in Samuel's state, and it will rеmain in the area in the next centuries.

North Macedonia's view
These fringe theories are still held mainly in North Macedonia, where the official state doctrine refers to an "Ethnic Macedonian" Empire, with Samuel being the first Tsar of the Macedonian Slavs. However, this controversy is ahistorical, as it projects modern ethnic distinctions onto the past. There is no historical support for that assertion. Samuel and his successors were never called by their contemporaries "Macedonians", but simply Bulgarians and rarely Misians. The last designation arose because then Bulgaria occupied traditionally the lands of the former Roman province of Moesia.

Macedonian historians insist also that the emperor Basil II designated the enemies coming from the Samuel’s Empire as “Scythians” in his epitaph and that the designation “Bulgaria” was used for ideological propaganda. This was newly introduced administrative term, by which the emperor ideologically framed the newly acquired territories of the former Bulgarian empire and the former Samuel’s State. In this way the term "Bulgarian" became a projected name for the Samuel’s State itself. However, the term “Scythians” normally referred to the "Bulgarians", moreover, Samuel and his successors considered their state Bulgarian.

Nevertheless, on a meeting in Sofia in June 2017, Prime Ministers Boyko Borisov and Zoran Zaev laid flowers at the monument of Tsar Samuil together, articulating optimism that the two countries can finally resolve their open issues by signing a long-delayed agreement on good-neighborly relations. The governments of Bulgaria and North Macedonia signed the friendship treaty in the same year, which was ratified by the two Parliaments in 2018. On its ground, a bilateral expert committee on historical issues was formed. In February 2019, at a meeting of the committee, involving Bulgarian and Macedonian scientists, the two sides agreed to propose to their governments that Tsar Samuel may be celebrated jointly. The Macedonian side also conceded, that he was Tsar of Bulgaria. Nevertheless in December 2020 North Macedonia's part from the joint committee withdrew from this decision. According to its view, Tsar Samuel had to be portrayed in one way in North Macedonia's textbooks, and in another during joint commemorations.

In August 2022, the Ministry of Foreign Affairs of North Macedonia published official recommendations of the Joint Historical Commission operating between the two countries. There, the governments in Sofia and Skopje are offered a joint commemoration of Samuel, who, according to the commission, was the ruler of a large medieval state, which the majority of modern historical scholarship considers to be the Bulgarian empire itself, centered in the territory of today's North Macedonia. In this way the Macedonian members of the Commission not only agreed to identify Samuel's state as Bulgarian, but they also recognized the existence of the Bulgarian ethnicity during the Middle Ages. Despite these facts multiple examples of animosity between Bulgaria and North Macedonia have been registered, due to disputes over Samuil's ethnic affiliation and this issue is still highly sensitive.

title: Samuel of Bulgaria


text: Talk:Metallurgy

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Talk:Metallurgy


text:
Escherichia coli O157:H7

Escherichia coli O157:H7 is a serotype of the bacterial species Escherichia coli and is one of the Shiga-like toxin–producing types of E. coli. It is a cause of disease, typically foodborne illness, through consumption of contaminated and raw food, including raw milk and undercooked ground beef. Infection with this type of pathogenic bacteria may lead to hemorrhagic diarrhea, and to kidney failure; these have been reported to cause the deaths of children younger than five years of age, of elderly patients, and of patients whose immune systems are otherwise compromised.

Transmission is via the fecal–oral route, and most illness has been through distribution of contaminated raw leaf green vegetables, undercooked meat and raw milk.

Signs and symptoms
E. coli O157:H7 infection often causes severe, acute hemorrhagic diarrhea (although nonhemorrhagic diarrhea is also possible) and abdominal cramps. Usually little or no fever is present, and the illness resolves in 5 to 10 days. It can also sometimes be asymptomatic.

In some people, particularly children under five years of age, persons whose immunologies are otherwise compromised, and the elderly, the infection can cause hemolytic–uremic syndrome (HUS), in which the red blood cells are destroyed and the kidneys fail. About 2–7% of infections lead to this complication. In the United States, HUS is the principal cause of acute kidney failure in children, and most cases of HUS are caused by E. coli O157:H7.

Bacteriology

Like the other strains of the E. coli, O157:H7 is gram-negative and oxidase-negative. Unlike many other strains, it does not ferment sorbitol, which provides a basis for clinical laboratory differentiation of the strain. Strains of E. coli that express Shiga and Shiga-like toxins gained that ability via infection with a prophage containing the structural gene coding for the toxin, and nonproducing strains may become infected and produce shiga-like toxins after incubation with shiga toxin positive strains. The prophage responsible seems to have infected the strain's ancestors fairly recently, as viral particles have been observed to replicate in the host if it is stressed in some way (e.g. antibiotics).

All clinical isolates of E. coli O157:H7 possess the plasmid pO157. The periplasmic catalase is encoded on pO157 and may enhance the virulence of the bacterium by providing additional oxidative protection when infecting the host. E. coli O157:H7 non-hemorrhagic strains are converted to hemorrhagic strains by lysogenic conversion after bacteriophage infection of non-hemorrhagic cells.

Natural habitat
While it is relatively uncommon, the E. coli serotype O157:H7 can naturally be found in the intestinal contents of some cattle, goats, and even sheep. The digestive tract of cattle lack the Shiga toxin receptor globotriaosylceramide, and thus, these can be asymptomatic carriers of the bacterium. The prevalence of E. coli O157:H7 in North American feedlot cattle herds ranges from 0 to 60%. Some cattle may also be so-called "super-shedders" of the bacterium. Super-shedders may be defined as cattle exhibiting rectoanal junction colonization and excreting >103 to 4 CFU g−1 feces. Super-shedders have been found to constitute a small proportion of the cattle in a feedlot (<10%) but they may account for >90% of all E. coli O157:H7 excreted.

Transmission
Infection with E. coli O157:H7 can come from ingestion of contaminated food or water, or oral contact with contaminated surfaces. Examples of this can be undercooked ground beef but also leafy vegetables and raw milk. Fields often become contaminated with the bacterium through irrigation processes or contaminated water naturally entering the soil. It is highly virulent, with a low infectious dose: an inoculation of fewer than 10 to 100 colony-forming units (CFU) of E. coli O157:H7 is sufficient to cause infection, compared to over a million CFU for other pathogenic E. coli strains.

Diagnosis
A stool culture can detect the bacterium. The sample is cultured on sorbitol-MacConkey (SMAC) agar, or the variant cefixime potassium tellurite sorbitol-MacConkey agar (CT-SMAC ). On SMAC agar, O157:H7 colonies appear clear due to their inability to ferment sorbitol, while the colonies of the usual sorbitol-fermenting serotypes of E. coli appear red. Sorbitol non-fermenting colonies are tested for the somatic O157 antigen before being confirmed as E. coli O157:H7. Like all cultures, diagnosis is time-consuming with this method; swifter diagnosis is possible using quick E. coli DNA extraction method plus polymerase chain reaction techniques. Newer technologies using fluorescent and antibody detection are also under development.

Prevention
Avoiding the consumption of, or contact with, unpasteurized dairy products, undercooked beef, uncleaned vegetables, and non disinfected water reduces the risk of an E. coli infection. Proper hand washing with water that has been treated with adequate levels of chlorine or other effective disinfectants after using the lavatory or changing a diaper, especially among children or those with diarrhea, reduces the risk of transmission.

Surveillance
E. coli O157:H7 infection is a nationally reportable disease in the US, Great Britain, and Germany. It is also reportable in most states of Australia including Queensland.

Treatment
While fluid replacement and blood pressure support may be necessary to prevent death from dehydration, most patients recover without treatment in 5–10 days. There is no evidence that antibiotics improve the course of disease, and treatment with antibiotics may precipitate hemolytic–uremic syndrome (HUS). The antibiotics are thought to trigger prophage induction, and the prophages released by the dying bacteria infect other susceptible bacteria, converting them into toxin-producing forms. Antidiarrheal agents, such as loperamide (imodium), should also be avoided as they may prolong the duration of the infection.

Certain novel treatment strategies, such as the use of anti-induction strategies to prevent toxin production and the use of anti-Shiga toxin antibodies, have also been proposed.

History
The first recorded observation of E. coli O157:H7 was in 1975, in association with a sporadic case of hemorrhagic colitis, but it was not identified as pathogenic then. It was first recognized as a human pathogen following a 1982 hemorrhagic colitis outbreak in Oregon and Michigan, in which at least 47 people were sickened by eating beef hamburger patties from a fast food chain that were found to be contaminated with it.

United States
The United States Department of Agriculture banned the sale of ground beef contaminated with the O157:H7 strain in 1994.

Costs
The pathogen results in an estimated 2,100 hospitalizations annually in the United States. The illness is often misdiagnosed; therefore, expensive and invasive diagnostic procedures may be performed. Patients who develop HUS often require prolonged hospitalization, dialysis, and long-term followup.

title: Escherichia coli O157:H7


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Frumenty

Frumenty (sometimes frumentee, furmity, fromity, or fermenty) was a popular dish in Western European medieval cuisine. It is a porridge, a thick boiled grain dish—hence its name, which derives from the Latin word frumentum, "grain". It was usually made with cracked wheat boiled with either milk or broth and was a peasant staple. More luxurious recipes include eggs, almonds, currants, sugar, saffron and orange flower water. Frumenty was served with meat as a pottage, traditionally with venison or even porpoise (considered a "fish" and therefore appropriate for Lent ). It was also frequently used as a subtlety, a dish between courses at a banquet.

History
Florence White, founder of the English Folk Cookery Association, wrote in Good Things in England (1932) that frumenty is England's "oldest national dish". For several centuries, frumenty was part of the traditional Celtic Christmas meal. According to an 1822 Time's Telescope, in Yorkshire, on Christmas Eve: "Supper is served, of which one dish, from the lordly mansion to the humblest shed, is, invariably, furmety; yule cake, one of which is always made for each individual in the family, and other more substantial viands are also added. Poor Robin, in his Almanack for the year 1676, (speaking of the winter quarter,) says, "and lastly, who would but praise it, because of Christmas, when good cheer doth so abound, as if all the world were made of minced pies, plum-pudding, and furmety [sic].""

It was often eaten on Mothering Sunday, the fourth Sunday of Lent, in late spring. On that day many servants were allowed to visit their mothers and were often served frumenty to celebrate and give them a wholesome meal to prepare them for their return journey. The use of eggs would have been a brief respite from the Lenten fast. In Lincolnshire, frumenty was associated with sheep-shearing in June. A diarist recalled of his youth in the 1820s that "almost every farmer in the village made a large quantity of frumenty on the morning they began to clip; and every child in the village was invited to partake of it". A second batch, of better quality, was produced later and taken round in buckets to every house in the village.

Food historian Polly Russell describes one of the first English recipes for it in the 1390 manuscript The Forme of Cury, and how this served as the inspiration for the 2013 Christmas menu at Dinner by Heston Blumenthal, transforming Victorian workhouse food for paupers into modern luxurious dining.

Literary references
Frumentee is served with venison at a banquet in the mid-14th century North Midlands poem Wynnere and Wastoure: "Venyson with the frumentee, and fesanttes full riche / Baken mete therby one the burde sett", i.e. in modern English, "Venison with the frumenty and pheasants full rich; baked meat by it on the table set". The dish also appears, likewise paired with venison, at the New Year feast in the Middle English poem known as The Alliterative Morte Arthure (c. 1400): "Flesh flourisht of fermison, with frumentee noble."

The dish, described as 'furmity' and served with fruit and a slug of rum added under the counter, plays a role in the plot of Thomas Hardy's novel The Mayor of Casterbridge. It is also mentioned in Lewis Carroll's Through the Looking-Glass as a food that snapdragon flies live on. Snapdragon was a popular game at Christmas, and Carroll's mention of frumenty shows it was known to him as a holiday food. It also appears in a girl's recitation of holiday traditions, in My Lady Ludlow, published 1858, by Elizabeth Gaskell: "furmenty on Mothering Sunday, Violet cakes in Passion Week" (Chapter 2).

Recipes
Steve Roud, librarian and folklorist, compiled a compendium of The English Year including three recipes for frumenty. They show considerable variation with place and time. "# The typical method of preparation was to parboil whole grains of wheat in water, then strain off and boil in milk, sweeten the boiled product with sugar, and flavour with cinnamon and other spices.
 * 1) Take clean wheat and bray it [beat it into small pieces ] in a mortar well that the hulls go all off [this means that the hulls are broken off], and seethe [boil] it till it burst, and take it up [drain it by taking it out of the water] and let it cool; and take fair fresh broth and sweet milk of almonds, or sweet milk of kine [cow's milk] and temper it all, and take yolks of eggs. Boil it a little and set it down and mess it forth ["mess" here in the sense of "plate and serve to table", the same root as naval mess] with fat venison and fresh mutton.
 * 2) Somerset–Wiltshire: About forty years ago [from an unspecified date] country women in shawls and sun bonnets used to come to the market at Weston-super-Mare in little carts carrying little basins of new wheat boiled to a jelly, which was put into a large pot with milk, eggs, and sultanas, and was lightly cooked; the resulting mixture was poured into pie-dishes and served on mid-Lent Sunday and during the ensuing week. Frumenty is still prepared at Devizes for Mothering Sunday."

A healthy dose of spirit is often mentioned as accompanying the frumenty.

Elsewhere
A dish made with boiled cracked wheat and soured milk was made in Ancient Persia, and is still used, often as the basis for a soup, in Greece and Cyprus (as trahanas), and in Turkey (tarhana). Kutia is an Eastern European dish with a similar recipe.

title: Frumenty


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L-system

An L-system or Lindenmayer system is a parallel rewriting system and a type of formal grammar. An L-system consists of an alphabet of symbols that can be used to make strings, a collection of production rules that expand each symbol into some larger string of symbols, an initial "axiom" string from which to begin construction, and a mechanism for translating the generated strings into geometric structures. L-systems were introduced and developed in 1968 by Aristid Lindenmayer, a Hungarian theoretical biologist and botanist at the University of Utrecht. Lindenmayer used L-systems to describe the behaviour of plant cells and to model the growth processes of plant development. L-systems have also been used to model the morphology of a variety of organisms and can be used to generate self-similar fractals.

Origins
As a biologist, Lindenmayer worked with yeast and filamentous fungi and studied the growth patterns of various types of bacteria, such as the cyanobacteria Anabaena catenula. Originally, the L-systems were devised to provide a formal description of the development of such simple multicellular organisms, and to illustrate the neighbourhood relationships between plant cells. Later on, this system was extended to describe higher plants and complex branching structures.

L-system structure
The recursive nature of the L-system rules leads to self-similarity and thereby, fractal-like forms are easy to describe with an L-system. Plant models and natural-looking organic forms are easy to define, as by increasing the recursion level the form slowly 'grows' and becomes more complex. Lindenmayer systems are also popular in the generation of artificial life.

L-system grammars are very similar to the semi-Thue grammar (see Chomsky hierarchy). L-systems are now commonly known as parametric L systems, defined as a tuple

 * G = (V, ω, P),

where

 * V (the alphabet) is a set of symbols containing both elements that can be replaced (variables) and those which cannot be replaced ("constants" or "terminals")
 * ω (start, axiom or initiator) is a string of symbols from V defining the initial state of the system
 * P is a set of production rules or productions defining the way variables can be replaced with combinations of constants and other variables. A production consists of two strings, the predecessor and the successor. For any symbol A which is a member of the set V which does not appear on the left hand side of a production in P, the identity production A → A is assumed; these symbols are called constants or terminals. (See Law of identity).

The rules of the L-system grammar are applied iteratively starting from the initial state. As many rules as possible are applied simultaneously, per iteration. The fact that each iteration employs as many rules as possible differentiates an L-system from a formal language generated by a formal grammar, which applies only one rule per iteration. If the production rules were to be applied only one at a time, one would quite simply generate a string in a language, and all such sequences of applications would produce the language specified by the grammar. There are some strings in some languages, however, that cannot be generated if the grammar is treated as an L-system rather than a language specification. For example, suppose there is a rule S→SS in a grammar. If productions are done one at a time, then starting from S, we can get first SS, and then, applying the rule again, SSS. However, if all applicable rules are applied at every step, as in an L-system, then we cannot get this sentential form. Instead, the first step would give us SS, but the second would apply the rule twice, giving us SSSS. Thus, the set of strings produced by an L-systems from a given grammar is a subset of the formal language defined by the grammar, and if we take a language to be defined as a set of strings, this means that a given L-system is effectively a subset of the formal language defined by the L-system's grammar.

An L-system is context-free if each production rule refers only to an individual symbol and not to its neighbours. Context-free L-systems are thus specified by a context-free grammar. If a rule depends not only on a single symbol but also on its neighbours, it is termed a context-sensitive L-system.

If there is exactly one production for each symbol, then the L-system is said to be deterministic (a deterministic context-free L-system is popularly called a D0L system). If there are several, and each is chosen with a certain probability during each iteration, then it is a stochastic L-system.

Using L-systems for generating graphical images requires that the symbols in the model refer to elements of a drawing on the computer screen. For example, the program Fractint uses turtle graphics (similar to those in the Logo programming language) to produce screen images. It interprets each constant in an L-system model as a turtle command.

Example 1: algae
Lindenmayer's original L-system for modelling the growth of algae.

 * variables :  A B
 * constants :  none
 * axiom    :   A
 * rules    :   (A → AB), (B → A)

which produces:

 * n = 0 : A
 * n = 1 : AB
 * n = 2 : ABA
 * n = 3 : ABAAB
 * n = 4 : ABAABABA
 * n = 5 : ABAABABAABAAB
 * n = 6 : ABAABABAABAABABAABABA
 * n = 7 : ABAABABAABAABABAABABAABAABABAABAAB

Example 1: algae, explained
n=0:              A             start (axiom/initiator) / \ n=1:            A   B           the initial single A spawned into AB by rule (A → AB), rule (B → A) couldn't be applied /|    \ n=2:           A B      A        former string AB with all rules applied, A spawned into AB again, former B turned into A              / | |       | \ n=3:        A B A       A B     note all A's producing a copy of themselves in the first place, then a B, which turns ... / | | | \    | \ \ n=4:       A B A A B     A B A   ... into an A one generation later, starting to spawn/repeat/recurse then

The result is the sequence of Fibonacci words. If we count the length of each string, we obtain the famous Fibonacci sequence of numbers (skipping the first 1, due to our choice of axiom):

 * 1 2  3  5  8  13  21  34  55 89 ...

If we would like to not skip the first 1, we can use axiom B. That would place B node before the topmost node (A) of the graph above.

For each string, if we count the k-th position from the left end of the string, the value is determined by whether a multiple of the golden ratio falls within the interval $$(k-1, k)$$. The ratio of A to B likewise converges to the golden mean.

This example yields the same result (in terms of the length of each string, not the sequence of As and Bs) if the rule (A → AB) is replaced with (A → BA), except that the strings are mirrored.

This sequence is a locally catenative sequence because $$G(n)=G(n-1)G(n-2)$$, where $$G(n)$$ is the n-th generation.

Example 2: fractal (binary) tree

 * variables : 0, 1
 * constants: "[", "]"
 * axiom : 0
 * rules : (1 → 11), (0 → 1[0]0)

The shape is built by recursively feeding the axiom through the production rules. Each character of the input string is checked against the rule list to determine which character or string to replace it with in the output string. In this example, a '1' in the input string becomes '11' in the output string, while ' [ ' remains the same. Applying this to the axiom of '0', we get:

We can see that this string quickly grows in size and complexity. This string can be drawn as an image by using turtle graphics, where each symbol is assigned a graphical operation for the turtle to perform. For example, in the sample above, the turtle may be given the following instructions:

 * 0: draw a line segment ending in a leaf
 * 1: draw a line segment
 * [ : push position and angle, turn left 45 degrees
 * ] : pop position and angle, turn right 45 degrees

The push and pop refer to a LIFO stack (more technical grammar would have separate symbols for "push position" and "turn left"). When the turtle interpretation encounters a ' [ ', the current position and angle are saved, and are then restored when the interpretation encounters a ' ] '. If multiple values have been "pushed," then a "pop" restores the most recently saved values. Applying the graphical rules listed above to the earlier recursion, we get:

Example 3: Cantor set

 * variables :  A B
 * constants :  none
 * start    :   A   {starting character string}
 * rules    :   (A → ABA), (B → BBB)

Let A mean "draw forward" and B mean "move forward".

This produces the famous Cantor's fractal set on a real straight line R.

Example 4: Koch curve
A variant of the Koch curve which uses only right angles.

 * variables :  F
 * constants :  + −
 * start    :   F
 * rules    :   (F → F+F−F−F+F)

Here, F means "draw forward", + means "turn left 90°", and − means "turn right 90°" (see turtle graphics).

 * n = 0:
 * F
 * square koch.svg

 * n = 1:
 * F+F−F−F+F
 * square koch 1.svg

 * n = 2:
 * F+F−F−F+F+F+F−F−F+F−F+F−F−F+F−F+F−F−F+F+F+F−F−F+F
 * square koch 2.svg

 * n = 3:
 * F+F−F−F+F+F+F−F−F+F−F+F−F−F+F−F+F−F−F+F+F+F−F−F+F+
 * F+F−F−F+F+F+F−F−F+F−F+F−F−F+F−F+F−F−F+F+F+F−F−F+F−
 * F+F−F−F+F+F+F−F−F+F−F+F−F−F+F−F+F−F−F+F+F+F−F−F+F−
 * F+F−F−F+F+F+F−F−F+F−F+F−F−F+F−F+F−F−F+F+F+F−F−F+F+
 * F+F−F−F+F+F+F−F−F+F−F+F−F−F+F−F+F−F−F+F+F+F−F−F+F
 * square koch 3.svg

Example 5: Sierpinski triangle
The Sierpinski triangle drawn using an L-system.

 * variables :  F G
 * constants :  + −
 * start    :   F−G−G
 * rules    :   (F → F−G+F+G−F), (G → GG)
 * angle    :   120°

Here, F and G both mean "draw forward", + means "turn left by angle", and − means "turn right by angle".

It is also possible to approximate the Sierpinski triangle using a Sierpiński arrowhead curve L-system.

 * variables :  A B
 * constants :  + −
 * start    :   A
 * rules    :   (A → B−A−B), (B → A+B+A)
 * angle    :   60°

Here, A and B both mean "draw forward", + means "turn left by angle", and − means "turn right by angle" (see turtle graphics).

Evolution for n = 2, n = 4, n = 6, n = 8

Example 6: dragon curve
The dragon curve drawn using an L-system.

 * variables :  F G
 * constants :  + −
 * start    :   F
 * rules    :   (F → F+G), (G → F-G)
 * angle    :   90°

Here, F and G both mean "draw forward", + means "turn left by angle", and − means "turn right by angle".

Dragon curve for n = 10

Example 7: fractal plant

 * variables :  X F
 * constants :  + − [ ]
 * start    :   X
 * rules    :   (X → F+[[X]-X]-F[-FX]+X), (F → FF)
 * angle    :   25°

First you need to initialize an empty stack. This follows the LIFO (Last in, First Out) method to add and remove elements. Here, F means "draw forward", − means "turn right 25°", and + means "turn left 25°". X does not correspond to any drawing action and is used to control the evolution of the curve. The square bracket "[" corresponds to saving the current values for position and angle, so you push the position and angle to the top of the stack, when the "]" token is encountered, pop the stack and reset the position and angle. Every "[" comes before every "]" token.

Fractal plant for n = 6

Variations
A number of elaborations on this basic L-system technique have been developed which can be used in conjunction with each other. Among these are stochastic grammars, context sensitive grammars, and parametric grammars.

Stochastic grammars
The grammar model we have discussed thus far has been deterministic—that is, given any symbol in the grammar's alphabet, there has been exactly one production rule, which is always chosen, and always performs the same conversion. One alternative is to specify more than one production rule for a symbol, giving each a probability of occurring. For example, in the grammar of Example 2, we could change the rule for rewriting "0" from:

 * 0 → 1[0]0

to a probabilistic rule:

 * 0 (0.5) → 1[0]0
 * 0 (0.5) → 0

Under this production, whenever a "0" is encountered during string rewriting, there would be a 50% chance it would behave as previously described, and a 50% chance it would not change during production. When a stochastic grammar is used in an evolutionary context, it is advisable to incorporate a random seed into the genotype, so that the stochastic properties of the image remain constant between generations.

Context sensitive grammars
A context sensitive production rule looks not only at the symbol it is modifying, but the symbols on the string appearing before and after it. For instance, the production rule:

 * b < a > c → aa

transforms "a" to "aa", but only if the "a" occurs between a "b" and a "c" in the input string:

 * …bac…

As with stochastic productions, there are multiple productions to handle symbols in different contexts. If no production rule can be found for a given context, the identity production is assumed, and the symbol does not change on transformation. If context-sensitive and context-free productions both exist within the same grammar, the context-sensitive production is assumed to take precedence when it is applicable.

Parametric grammars
In a parametric grammar, each symbol in the alphabet has a parameter list associated with it. A symbol coupled with its parameter list is called a module, and a string in a parametric grammar is a series of modules. An example string might be:

 * a(0,1)[b(0,0)]a(1,2)

The parameters can be used by the drawing functions, and also by the production rules. The production rules can use the parameters in two ways: first, in a conditional statement determining whether the rule will apply, and second, the production rule can modify the actual parameters. For example, look at:

 * a(x,y) : x == 0 → a(1, y+1)b(2,3)

The module a(x,y) undergoes transformation under this production rule if the conditional x=0 is met. For example, a(0,2) would undergo transformation, and a(1,2) would not.

In the transformation portion of the production rule, the parameters as well as entire modules can be affected. In the above example, the module b(x,y) is added to the string, with initial parameters (2,3). Also, the parameters of the already existing module are transformed. Under the above production rule,

 * a(0,2)

Becomes

 * a(1,3)b(2,3)

as the "x" parameter of a(x,y) is explicitly transformed to a "1" and the "y" parameter of a is incremented by one.

Parametric grammars allow line lengths and branching angles to be determined by the grammar, rather than the turtle interpretation methods. Also, if age is given as a parameter for a module, rules can change depending on the age of a plant segment, allowing animations of the entire life-cycle of the tree to be created.

Bi-directional grammars
The bi-directional model explicitly separates the symbolic rewriting system from the shape assignment. For example, the string rewriting process in the Example 2 (Fractal tree) is independent on how graphical operations are assigned to the symbols. In other words, an infinite number of draw methods are applicable to a given rewriting system.

The bi-directional model consists of 1) a forward process constructs the derivation tree with production rules, and 2) a backward process realizes the tree with shapes in a stepwise manner (from leaves to the root). Each inverse-derivation step involves essential geometric-topological reasoning. With this bi-directional framework, design constraints and objectives are encoded in the grammar-shape translation. In architectural design applications, the bi-directional grammar features consistent interior connectivity and a rich spatial hierarchy.

Open problems
There are many open problems involving studies of L-systems. For example:

 * Characterisation of all the deterministic context-free L-systems which are locally catenative. (A complete solution is known only in the case where there are only two variables).
 * Given a structure, find an L-system that can produce that structure.

Types of L-systems
L-systems on the real line R:
 * Prouhet-Thue-Morse system

Well-known L-systems on a plane R2 are:
 * space-filling curves (Hilbert curve, Peano's curves, Dekking's church, kolams),
 * median space-filling curves (Lévy C curve, Harter-Heighway dragon curve, Davis-Knuth terdragon),
 * tilings (sphinx tiling, Penrose tiling)

Books

 * Przemysław Prusinkiewicz, Aristid Lindenmayer – The Algorithmic Beauty of Plants PDF version available here for free
 * Grzegorz Rozenberg, Arto Salomaa – Lindenmayer Systems: Impacts on Theoretical Computer Science, Computer Graphics, and Developmental Biology ISBN 978-3-540-55320-5
 * D.S. Ebert, F.K. Musgrave, et al. – Texturing and Modeling: A Procedural Approach, ISBN 0-12-228730-4
 * Burry, Jane, Burry Mark, (2010). The New Mathematics of Architecture, New York: Thames and Hudson.
 * Aristid Lindenmayer, "Mathematical models for cellular interaction in development." J. Theoret. Biology, 18:280—315, 1968.

title: L-system


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Bread pudding

Bread pudding is a bread-based dessert popular in many countries' cuisines. It is made with stale bread and milk or cream, generally containing eggs, a form of fat such as oil, butter or suet and, depending on whether the pudding is sweet or savory, a variety of other ingredients. Sweet bread puddings may use sugar, syrup, honey, dried fruit, nuts, as well as spices such as cinnamon, nutmeg, mace, or vanilla. The bread is soaked in the liquids, mixed with the other ingredients, and baked.

Savory puddings like breakfast strata may be served as main courses, while sweet puddings are typically eaten as desserts.

In other languages, its name is a translation of "bread pudding" or even just "pudding", for example "pudín" or "budín". In the Philippines, banana bread pudding is popular. In Mexico, there is a similar dish eaten during Lent called capirotada. In Liverpool in the United Kingdom, a moist version of Nelson cake, itself a bread pudding, is nicknamed "Wet Nelly".

History
Bread pudding originated with 11th-century English cooks who repurposed leftover stale bread. In the following centuries, the dish became known as "poor man's pudding" because of the scarcity of food at the time, with the pudding being made only with boiling water, sugar, and spices.

It was only in the 13th century that eggs and milk were added to the recipe, which then became known as "bread and butter pudding". The 18th-century English cookbook The Compleat Housewife contains two recipes for baked bread pudding. The first is identified as "A Bread and Butter Pudding for Fasting Days". To make the pudding a baking dish is lined with puff pastry, and slices of penny loaf with butter, raisins and currants, and pieces of butter are added in alternating layers. Over this is poured thickened, spiced cream and orange blossom water, and the dish is baked in the oven. There is another version of the dish that is simpler, omitting the spices and dried fruits.

With the arrival of the first settlers in the 13 English Colonies in America, bread pudding became popular in the colonies and later in the United States.

Regional variations
In Belgium, particularly Brussels, bread pudding is baked with brown sugar, cinnamon, stale bread, and raisins or apple.

In Canada, bread pudding is sometimes made with maple syrup.

In Hong Kong, bread pudding is usually served with vanilla cream dressing.

In Hungary, it is called Máglyarakás (literally, "bonfire") which is baked with whipped egg whites on top.

In Malaysia, bread pudding is eaten with custard sauce.

In Mecklenburg-Vorpommern, Germany, black bread is used to make "black bread pudding" (Schwarzbrotpudding).

In the Philippines, stale unsold bread are commonly used by bakeries to make the characteristically bright red filling of pan de regla.

In the United States, especially Louisiana, bread puddings are typically sweet and served as dessert with a sweet sauce of some sort, such as whiskey sauce, rum sauce, or caramel sauce, but typically sprinkled with sugar and eaten warm in squares or slices. Sometimes, bread pudding is served warm topped with or alongside a dollop of whipped cream or a scoop of vanilla ice cream. In Puerto Rico, there are many variations of bread pudding on the island. Cream cheese with lime zest and guava or coconut-sweet plantain with rum raisins is perhaps the most popular. Bread pudding is always made with a variety of spices. Puerto Rican bread pudding is cooked the same as crème caramel with caramel poured into a baking dish and then the pudding mix is poured on top. The baking dish is placed in a bain-marie and then in the oven.

In Argentina, Peru, Paraguay, and Uruguay, bread pudding is known as "budín de pan". In Brazil, bread pudding is known as "pudim de pão". The dish consists of bread, eggs, milk, condensed milk, butter, vanilla extract, and a pinch of cinnamon (optional). However, all the ingredients are mixed together in a blender and poured into a bundt-like mold (with a hole in the middle) lined with caramelized sugar syrup, which is then baked in a water bath for about 1 hour and a half. Afterwards, it is left to cool before unmolding and serving. When ready, its appearance can be compared to a creamy yet dense flan.

In Panama, bread pudding is known as "mamallena".

In Aruba, bread pudding is known as "pan bolo".

In Cuba, bread pudding is known as "pudín de pan" and many serve it with a guava marmalade.

In Chile, bread pudding is known as "colegial" or "budín de pan".

In Mexico it is simply known as "budín" and is usually made with bolillo leftovers. It's typically made with raisins and pecans.

In Czech Republic and Slovakia bread pudding is known as "žemľovka" and is most commonly made of apples and rohlíks or veka, soaked in sweet milk.

In Southeast Asian regions like Malaysia, Singapore, and Indonesia, bread pudding is sometimes found in local dessert shops. To cater to local preferences, it may incorporate ingredients such as coconut milk, pandan leaves, palm sugar, and tropical fruits.

In Turkey, bread pudding is known as ekmek kadayıfı and served with a slice of kaymak or ice cream on top of the cake which is garnished with ground pistachio or shredded coconut.

In Myanmar, bread pudding known as "Pu Tin" in Burmese has been a popular dessert since colonial times. It is also added to a desert known as Falooda.

In Bangladesh, a variation of bread pudding called Shahi Tukra, has existed in the region since Mughal times. Shahi Tukra (also spelled Tukda) is known in Hyderabad as Double Ka Meetha.

title: Bread pudding


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Batavia (region)

Batavia (Betuwe, ) is a historical and geographical region in the Netherlands, forming large fertile islands in the river delta formed by the waters of the Rhine (Dutch: Rijn) and Meuse (Dutch: Maas) rivers. During the Roman Empire, it was an important frontier region and source of imperial soldiers. Its name is possibly pre-Roman.

Administratively, the modern version, Betuwe, is a part of the modern province of Gelderland and although the rivers and provinces have changed over history it is roughly the same. Today it has the Waal river on the south and the Lek and Nederrijn in the north (all rivers which start in the delta itself and are branches of the Rhine or Maas). Historically, the former municipality of Rijnwaarden belonged to Betuwe, now in Zevenaar, which was cut off by the building of the Pannerdens Kanaal.

A major freight railroad, the Betuweroute, passes through the Betuwe. It was opened in 2007 after many years of controversy. The Betuwe region is divided into nine municipalities: Lingewaard, Arnhem (southern part), Nijmegen (northern part), Overbetuwe, Neder-Betuwe, Buren, Tiel, Culemborg and West Betuwe. The region is characterised by its many orchards, and is for centuries known as the fruit garden of the Netherlands.

Pre-Roman
The "Batavian island" in the Rhine river was mentioned by Julius Caesar in his commentary Commentarii de Bello Gallico. The island's easternmost point is at a split in the Rhine, one arm being the Waal and the other the Lower Rhine/Old Rhine (hence the Latin name Insula Batavorum, "Island of the Batavi"). Much later Tacitus wrote that the Batavians who lived there had originally been a part of the Chatti, a tribe in Germany never mentioned by Caesar, who were forced by internal dissension to move to their new home.

Tacitus also reports that before their arrival the area had been "an uninhabited district on the extremity of the coast of Gaul, and also of a neighbouring island, surrounded by the ocean in front, and by the river Rhine in the rear and on either side". In a more detailed description he writes: "The island of the Batavi was the appointed rendezvous because of its easy landing-places, and its convenience for receiving the army and carrying the war across the river. For the Rhine after flowing continuously in a single channel or encircling merely insignificant islands, divides itself, so to say, where the Batavian territory begins, into two rivers, retaining its name and the rapidity of its course in the stream which washes Germany, till it mingles with the ocean. On the Gallic bank, its flow is broader and gentler; it is called by an altered name, the Vahal, by the inhabitants of its shore. Soon that name too is changed for the Mosa river, through whose vast mouth it empties itself into the same ocean."

Modern archaeologists disagree with Tacitus, noting that that island had a pre-Roman and pre-Germanic population, apparently already called the Batavians. Caesar indeed had not only implied the existence of pre-Roman Batavians, but also mentioned that the Belgic Menapii of the Flemish coast had settlements stretching as far as the beginning of the delta, near the modern border with Germany.

Roman era
During the Roman Empire there was a civitas of the Batavians, a Germanic tribe. It was described as a large island between rivers in the Rhine-Meuse delta, the modern equivalent of Betuwe. The Batavians shared the island with the Canninefates, to their west near the coast. Their Roman city was Nijmegen.

The name was also mentioned by Pliny the Elder, and it played a role in the account by Tacitus of the Germanic uprising of 68. He said that "In the Rhine itself, nearly 100 mi in length, Batavia is the most famous island of the Batavi and the Canninefates".

Its later Roman history is attested by Ammianus Marcellinus who mentions the Frankish Salians as a people living there. Zosimus is the only classical author who claims that they had first crossed the Rhine during the Roman upheavals and subsequent Germanic breakthrough in 260 AD. Both authors agree that from Batavia they were pushed south, into Toxandria.

Medieval
In the Carolingian and Ottonian periods in the early Middle Ages, Batavia, called Batua by the Franks, was an example of a Frankish gau that was based on much older Roman pagi. Several counts are recorded as having their counties there, and it is mentioned in the treaties such as the Treaty of Meerssen, that divided up Europe among the different Frankish kingdoms.

Later, it was mainly absorbed into the newer county of Guelders which had become established to the southeast.

Renaissance
In the Renaissance, the Dutch wanted to rediscover their pre-medieval Batavi culture and history. This common history raised Batavi to the status of cultural ancestors to all Dutch people (see The Batavian revival). They occasionally called themselves, or their things (Batavia), Batavians, resulting even in a short-lived Batavian Republic. The name Batavia was also taken to the colonies such as the Dutch East Indies, where they renamed the city of Jayakarta to become Batavia from 1619 until about 1942, when its name was changed to Djakarta (short for the former name Jayakarta, later respelt Jakarta; see: History of Jakarta). The name was also used in Suriname, where they founded Batavia, Suriname, and in the United States where the Holland Land Company founded the city and the town of Batavia, New York. This name spread further west in the United States to such places as Batavia, Illinois, near Chicago, and Batavia, Ohio.

When the Pannerdens Kanaal was dug between 1701 and 1709, the easternmost tip of the Betuwe (including the towns of Pannerden and Lobith) was cut off from the rest of the region.

20th century
In the aftermath of the failed allied Operation Market Garden, the Germans attempted to retake the Allied gains during the Battle of the Nijmegen salient but were unsuccessful.

In the period 1940-1990, land consolidation took place throughout the area. This made further economies of scale and departmentalisation in the fruit production possible.

In 1995, a large part of this area had to be evacuated because the rivers threatened to overflow. This did not happen, but it raised the debate again about whether to reinforce the dikes.

title: Batavia (region)


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Oat

The oat (Avena sativa), sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural, unlike other cereals and pseudocereals). Oats are used for human consumption as oatmeal, including as steel cut oats or rolled oats. They appear to have been domesticated as a secondary crop as their seeds resembled those of other cereals closely enough for them to be included by early cultivators. Oats are a nutrient-rich food associated with lower blood cholesterol and reduced risk of human heart disease when consumed regularly. One of the most common uses of oats is as livestock feed; the crop can also be grown as groundcover and ploughed in as a green manure.

Phylogeny

Phylogenetic analysis using molecular DNA and morphological evidence places the oat genus Avena in the Pooideae subfamily. That subfamily includes the cereals wheat, barley, and rye; they are in the Triticeae tribe, while Avena is in the Poeae, along with grasses such as Briza and Agrostis. The wild ancestor of Avena sativa and the closely related minor crop – A. byzantina – is A. sterilis, a naturally hexaploid wild oat, one that has its DNA in six sets of chromosomes. Genetic evidence shows that the ancestral forms of A. sterilis grew in the Fertile Crescent of the Near East.

Analysis of maternal lineages of 25 Avena species using chloroplast and mitochondrial DNA showed that A. sativa hexaploid (AACCDD) genome derives from three diploid oat species (each with two sets of chromosomes), namely the CC A. ventricosa, the AA A. canariensis, and the AA A. longiglumis, along with two tetraploid oats (each with four sets), namely the AACC A. insularis and the AABB A. agadiriana. Tetraploids were formed as much as 10.6 mya, and hexaploids as much as 7.4 mya.

Domestication
Genomic study suggests that the hulled variety and the naked variety ''A. sativa var. nuda'' diverged around 51,200 years ago, long before domestication. This implies that the two varieties were domesticated independently.

Oats are thought to have emerged as a secondary crop. This means that they are derived from what was considered a weed of the primary cereal domesticates such as wheat. They survived as a Vavilovian mimic by having grains that Neolithic people found hard to distinguish from the primary crop.

Oats were cultivated for some thousands of years before they were domesticated. A granary from the Pre-Pottery Neolithic, some 11,400 to 11,200 years ago in the Jordan Valley in the Middle East contained a large number of wild oat grains (120,000 seeds of A. sterilis). The find implies intentional cultivation. Domesticated oat grains first appear in the archaeological record in Europe around 3000 years ago.

Description
The oat is a tall stout grass, a member of the family Poaceae; it grows to a height of some 1.8 m. The leaves are long, narrow, and pointed, and grow upwards; they can be some 15 to 40 cm in length, and around 5 to 15 mm in width. At the top of the stem, the plant branches into a loose cluster or panicle of spikelets. These contain the wind-pollinated flowers, which mature into the oat seeds or grains. Botanically the grain is a caryopsis, as the wall of the fruit is fused on to the actual seed. Like other cereal grains, the caryopsis contains the outer husk or bran, the starchy food store or endosperm which occupies most of the seed, and the protein-rich germ which if planted in the soil can grow into a new plant.

Cultivation
Oats are annual plants best grown in temperate regions. They have a lower summer heat requirement and greater tolerance of (and need for) rain than other cereals, such as wheat, rye or barley, so they are particularly important in areas with cool, wet summers, such as Northwest Europe.

Oats can grow in most fertile, drained soils, being tolerant of a wide variety of soil types. Although better yields are achieved at a soil pH of 5.3 to 5.7, oats can tolerate soils with a pH as low as 4.5. They are better able to grow in low-nutrient soils than wheat or maize, but generally are less tolerant of high soil salinity.

Oats are sown in the spring or early summer in colder areas, as soon as the soil can be worked, for harvest in the autumn. An early start is crucial to good fields, as the plants go dormant in summer heat. In warmer areas, oats are sown in late summer or early fall, for harvest the following summer. Oats are cold-tolerant and are unaffected by late frosts or snow.

Weeds, pests and diseases

Oats can outcompete many weeds, as they grow thickly (with many leafy shoots) and vigorously, but are still subject to some broadleaf weeds. Control can be by herbicides, or by integrated pest management with measures such as sowing seed that is free of weeds.

Oats are relatively free from diseases and pests. Nonetheless, they suffer from some leaf diseases, such as leaf rust, stem rust (Puccinia graminis f. sp. avenae), and crown rust (P. coronata var. avenae).

Crown rust infection can greatly reduce photosynthesis and overall physiological activities of oat leaves, thereby reducing growth and crop yield.

Processing

Harvested oats go through multiple stages of milling. The first stage is cleaning, to remove seeds of other plants, stones and any other extraneous materials. Next is dehulling to remove the indigestible bran, leaving the seed or "groat". Heating denatures enzymes in the seed that would make it go sour or rancid; the grain is then dried to minimise the risk of spoilage by bacteria and fungi. There may follow numerous stages of cutting or grinding the grain, depending on which sort of product is required. For oatmeal (oat flour), the grain is ground to a specified fineness. For home use such as making porridge, oats are often rolled flat to make them quicker to cook.

Oat flour can be ground for small scale use by pulsing rolled oats or old-fashioned (not quick) oats in a food processor or spice mill.

Production and trade
In 2022, global production of oats was 26 million tonnes, led by Canada with 20% of the total and Russia with 17% (table). This compares to over 100 million tonnes for wheat, for example. Global trade represents a modest percentage of production, less than 10%, most of the grain being consumed within producing countries. The main exporter is Canada, followed by Sweden and Finland; the US is the main importer.

Oats futures are traded in US dollars in quantities of 5000 bushels on the Chicago Board of Trade and have delivery dates in March, May, July, September, and December.

Genome
Avena sativa is an allohexaploid species with three ancestral genomes (2n=6x=42; AACCDD). As a result, the genome is large (12.6 Gb, 1C-value=12.85) and complex. Cultivated hexaploid oat has a unique mosaic chromosome architecture that is the result of numerous translocations between the three subgenomes. These translocations may cause breeding barriers and incompatibilities when crossing varieties with different chromosomal architecture. Hence, oat breeding and the crossing of desired traits has been hampered by the lack of a reference genome assembly. In May 2022, a fully annotated reference genome sequence of Avena sativa was reported. The AA subgenome is presumed to be derived from Avena longiglumis and the CCDD from the tetraploid Avena insularis.

Genetics and breeding
Species of Avena can hybridize and genes introgressed from other "A" genome species have contributed many valuable traits, like resistance to oat crown rust. is one such trait, introgressed from A. sterilis CAV 1979, conferring all stage resistance (ASR) against Pca.

It is possible to hybridize oats with grasses in other genera, allowing plant breeders the ready introgression of traits. In contrast to wheat, oats sometimes retain chromosomes from maize or pearl millet after such crosses. These wide crosses are typically made to generate doubled haploid breeding material, where the rapid loss of the alien chromosomes from the unrelated pollen donor results in a plant with only a single set of chromosomes (a haploid).

The addition lines with alien chromosomes can be used as a source for novel traits in oats, for example, research on oat-maize-addition lines has been used to map genes involved in C4 photosynthesis. To obtain Mendelian inheritance of these novel traits, radiation hybrid lines have been established, where maize chromosome segments have been introgressed into the oat genome. This technique – which potentially transfers thousands of genes from a species that is distantly related – is not considered a GMO technique, according to the European Union definition, since sexual hybridization and radiation-induced introgression are explicitly excluded.

A 2013 study applied simple sequence repeat and found five major groupings, namely commercial cultivars and four landrace groups.

Nutrients
Uncooked oats are 66% carbohydrates, including 11% dietary fiber and 4% beta-glucans, 7% fat, 17% protein, and 8% water (table). In a reference serving of 100 g, oats provide 389 kcal and are a rich source (20% or more of the Daily Value, DV) of protein (34% DV), dietary fiber (44% DV), several B vitamins, and numerous dietary minerals, especially manganese (213% DV) (table).

Health effects
Chronic consumption of oat products lowers blood levels of low-density lipoprotein and total cholesterol, reducing the risk of cardiovascular disease. The benefical effect of oat consumption on lowering blood lipids is attributed to oat beta-glucan. Oat consumption can help to reduce body mass index in obese people.

The United States Food and Drug Administration allows companies to make health claims on labels of food products that contain soluble fiber from whole oats, as long as the food provides 0.75 grams of soluble fiber per serving.

As food
Oats have numerous uses in foods; most commonly, they are rolled or crushed into oatmeal, or ground into fine oat flour. Oatmeal is chiefly eaten as porridge, but may also be used in a variety of baked goods, such as oatcakes (which may be made with coarse steel-cut oats for a rougher texture), oatmeal cookies and oat bread. Oats are an ingredient in many cold cereals, in particular muesli and granola. Oats are also used for production of milk substitutes ("oat milk"). As of late 2020, the oat milk market became the second-largest among plant milks in the United States, following the leader, almond milk, but exceeding the sales of soy milk.

In Britain, oats are sometimes used for brewing beer, such as oatmeal stout where a percentage of oats, often 30%, is added to the barley for the wort. Oatmeal caudle, made of ale and oatmeal with spices, was a traditional British drink and a favourite of Oliver Cromwell.

Animal feed

Oats are commonly used as feed for horses when extra carbohydrates and the subsequent boost in energy are required. The oat hull may be crushed ("rolled" or "crimped") for the horse to more easily digest the grain, or may be fed whole. They may be given alone or as part of a blended food pellet. Cattle are also fed oats, either whole or ground into a coarse flour using a roller mill, burr mill, or hammermill. Oat forage is commonly used to feed all kinds of ruminants, as pasture, straw, hay or silage.

Ground cover
Winter oats may be grown as an off-season groundcover and ploughed under in the spring as a green fertilizer, or harvested in early summer. They also can be used for pasture; they can be grazed a while, then allowed to head out for grain production, or grazed continuously until other pastures are ready.

Other uses
Oat straw is used as animal bedding; it absorbs liquids better than wheat straw. The straw can be used for making corn dollies, small decorative woven figures. Tied in a muslin bag, oat straw has been used to soften bath water.

Celiac disease
Celiac (or coeliac) disease is a permanent autoimmune disease triggered by gluten proteins. It almost always occurs in genetically predisposed people, having a prevalence of about 1% in the developed world. Oat products are frequently contaminated by other gluten-containing grains, mainly wheat and barley, requiring caution in the use of oats if people are sensitive to the gluten in those grains. For example, oat bread often contains only a small proportion of oats alongside wheat or other cereals. Use of pure oats in a gluten-free diet offers improved nutritional value, but remains controversial because a small proportion of people with celiac disease react to pure oats.

In human culture
In his 1755 Dictionary of the English Language, Samuel Johnson defined oats as "A grain, which in England is generally given to horses, but in Scotland supports the people."

"Oats and Beans and Barley Grow" is the first line of a traditional folksong (1380 in the Roud Folk Song Index), recorded in different forms from 1870. Similar songs are recorded from France, Canada, Belgium, Sweden, and Italy.

In English, oats are associated with sexual intercourse, as in the idioms "sowing one's (wild) oats", meaning having many sexual partners in one's youth, and "getting your oats", meaning having sex regularly.

title: Oat