Odrysian golden wreath in the National History Museum

Neanderthal remains dating to around 150,000 years ago, or the Middle Paleolithic, are some of the earliest traces of human activity in the lands of modern Bulgaria.[1] Remains from Homo sapiens found there are dated c. 47,000 years BP. This result represents the earliest arrival of modern humans in Europe.[2][3] The Karanovo culture arose circa 6,500 BC and was one of several Neolithic societies in the region that thrived on agriculture.[4] The Copper Age Varna culture (fifth millennium BC) is credited with inventing gold metallurgy.[5][6] The associated Varna Necropolis treasure contains the oldest golden jewellery in the world with an approximate age of over 6,000 years.[7][8] The treasure has been valuable for understanding social hierarchy and stratification in the earliest European societies.[9][10][11]

The Thracians, one of the three primary ancestral groups of modern Bulgarians, appeared on the Balkan Peninsula some time before the 12th century BC.[12][13][14] The Thracians excelled in metallurgy and gave the Greeks the Orphean and Dionysian cults, but remained tribal and stateless.[15] The Persian Achaemenid Empire conquered parts of present-day Bulgaria (in particular eastern Bulgaria) in the 6th century BC and retained control over the region until 479 BC.[16][17] The invasion became a catalyst for Thracian unity, and the bulk of their tribes united under king Teres to form the Odrysian kingdom in the 470s BC.[15][17][18] It was weakened and vassalised by Philip II of Macedon in 341 BC,[19] attacked by Celts in the 3rd century,[20] and finally became a province of the Roman Empire in AD 45.[21]

By the end of the 1st century AD, Roman governance was established over the entire Balkan Peninsula and Christianity began spreading in the region around the 4th century.[15] The Gothic Bible—the first Germanic language book—was created by Gothic bishop Ulfilas in what is today northern Bulgaria around 381.[22] The region came under Byzantine control after the fall of Rome in 476. The Byzantines were engaged in prolonged warfare against Persia and could not defend their Balkan territories from barbarian incursions.[23] This enabled the Slavs to enter the Balkan Peninsula as marauders, primarily through an area between the Danube River and the Balkan Mountains known as Moesia.[24] Gradually, the interior of the peninsula became a country of the South Slavs, who lived under a democracy.[25][26] The Slavs assimilated the partially Hellenised, Romanised, and Gothicised Thracians in the rural areas.[27][28][29][30]

 

Knyaz Boris I meeting the disciples of Saints Cyril and Methodius.

Not long after the Slavic incursion, Moesia was once again invaded, this time by the Bulgars under Khan Asparukh.[31] Their horde was a remnant of Old Great Bulgaria, an extinct tribal confederacy situated north of the Black Sea in what is now Ukraine and southern Russia. Asparukh attacked Byzantine territories in Moesia and conquered the Slavic tribes there in 680.[13] A peace treaty with the Byzantine Empire was signed in 681, marking the foundation of the First Bulgarian Empire. The minority Bulgars formed a close-knit ruling caste.[32]

Succeeding rulers strengthened the Bulgarian state throughout the 8th and 9th centuries. Krum introduced a written code of law[33] and checked a major Byzantine incursion at the Battle of Pliska, in which Byzantine emperor Nicephorus I was killed.[34] Boris I abolished paganism in favour of Eastern Orthodox Christianity in 864. The conversion was followed by a Byzantine recognition of the Bulgarian church[35] and the adoption of the Cyrillic alphabet, developed in the capital, Preslav.[36] The common language, religion and script strengthened central authority and gradually fused the Slavs and Bulgars into a unified people speaking a single Slavic language.[37][36] A golden age began during the 34-year rule of Simeon the Great, who oversaw the largest territorial expansion of the state.[38]

After Simeon's death, Bulgaria was weakened by wars with Magyars and Pechenegs and the spread of the Bogomil heresy.[37][39] Preslav was seized by the Byzantine army in 971 after consecutive Rus' and Byzantine invasions.[37] The empire briefly recovered from the attacks under Samuil,[40] but this ended when Byzantine emperor Basil II defeated the Bulgarian army at Klyuch in 1014. Samuil died shortly after the battle,[41] and by 1018 the Byzantines had conquered the First Bulgarian Empire.[42] After the conquest, Basil II prevented revolts by retaining the rule of local nobility, integrating them in Byzantine bureaucracy and aristocracy, and relieving their lands of the obligation to pay taxes in gold, allowing tax in kind instead.[43][44] The Bulgarian Patriarchate was reduced to an archbishopric, but retained its autocephalous status and its dioceses.[44][43]

 

The walls of Tsarevets fortress in Veliko Tarnovo, the capital of the second empire

Byzantine domestic policies changed after Basil's death and a series of unsuccessful rebellions broke out, the largest being led by Peter Delyan. The empire's authority declined after a catastrophic military defeat at Manzikert against Seljuk invaders, and was further disturbed by the Crusades. This prevented Byzantine attempts at Hellenisation and created fertile ground for further revolt. In 1185, Asen dynasty nobles Ivan Asen I and Peter IV organised a major uprising and succeeded in re-establishing the Bulgarian state. Ivan Asen and Peter laid the foundations of the Second Bulgarian Empire with its capital at Tarnovo.[45]

Kaloyan, the third of the Asen monarchs, extended his dominion to Belgrade and Ohrid. He acknowledged the spiritual supremacy of the pope and received a royal crown from a papal legate.[46] The empire reached its zenith under Ivan Asen II (1218–1241), when its borders expanded as far as the coast of Albania, Serbia and Epirus, while commerce and culture flourished.[46][45] Ivan Asen's rule was also marked by a shift away from Rome in religious matters.[47]

The Asen dynasty became extinct in 1257. Internal conflicts and incessant Byzantine and Hungarian attacks followed, enabling the Mongols to establish suzerainty over the weakened Bulgarian state.[46][47] In 1277, swineherd Ivaylo led a great peasant revolt that expelled the Mongols from Bulgaria and briefly made him emperor.[48][45] He was overthrown in 1280 by the feudal landlords,[48] whose factional conflicts caused the Second Bulgarian Empire to disintegrate into small feudal dominions by the 14th century.[45] These fragmented rump states—two tsardoms at Vidin and Tarnovo and the Despotate of Dobrudzha—became easy prey for a new threat arriving from the Southeast: the Ottoman Turks.[46]

 

The Battle of Nicopolis in 1396 marked the end of medieval Bulgarian statehood.

The Ottomans were employed as mercenaries by the Byzantines in the 1340s but later became invaders in their own right.[49] Sultan Murad I took Adrianople from the Byzantines in 1362; Sofia fell in 1382, followed by Shumen in 1388.[49] The Ottomans completed their conquest of Bulgarian lands in 1393 when Tarnovo was sacked after a three-month siege and the Battle of Nicopolis which brought about the fall of the Vidin Tsardom in 1396. Sozopol was the last Bulgarian settlement to fall, in 1453.[50] The Bulgarian nobility was subsequently eliminated and the peasantry was enserfed to Ottoman masters,[49] while much of the educated clergy fled to other countries.[51]

Bulgarians were subjected to heavy taxes (including Devshirme, or blood tax), their culture was suppressed,[51] and they experienced partial Islamisation.[52] Ottoman authorities established a religious administrative community called the Rum Millet, which governed all Orthodox Christians regardless of their ethnicity.[53] Most of the local population then gradually lost its distinct national consciousness, identifying only by its faith.[54][55] The clergy remaining in some isolated monasteries kept their ethnic identity alive, enabling its survival in remote rural areas,[56] and in the militant Catholic community in the northwest of the country.[57]

As Ottoman power began to wane, Habsburg Austria and Russia saw Bulgarian Christians as potential allies. The Austrians first backed an uprising in Tarnovo in 1598, then a second one in 1686, the Chiprovtsi Uprising in 1688 and finally Karposh's Rebellion in 1689.[58] The Russian Empire also asserted itself as a protector of Christians in Ottoman lands with the Treaty of Küçük Kaynarca in 1774.[58]

 

The Russo-Bulgarian defence of Shipka Pass in 1877

The Western European Enlightenment in the 18th century influenced the initiation of a national awakening of Bulgaria.[49] It restored national consciousness and provided an ideological basis for the liberation struggle, resulting in the 1876 April Uprising. Up to 30,000 Bulgarians were killed as Ottoman authorities put down the rebellion. The massacres prompted the Great Powers to take action.[59] They convened the Constantinople Conference in 1876, but their decisions were rejected by the Ottomans. This allowed the Russian Empire to seek a military solution without risking confrontation with other Great Powers, as had happened in the Crimean War.[59] In 1877, Russia declared war on the Ottomans and defeated them with the help of Bulgarian rebels, particularly during the crucial Battle of Shipka Pass which secured Russian control over the main road to Constantinople.[60][61]

The Treaty of San Stefano was signed on 3 March 1878 by Russia and the Ottoman Empire. It was to set up an autonomous Bulgarian principality spanning Moesia, Macedonia and Thrace, roughly on the territories of the Second Bulgarian Empire,[62][63] and this day is now a public holiday called National Liberation Day.[64] The other Great Powers immediately rejected the treaty out of fear that such a large country in the Balkans might threaten their interests. It was superseded by the Treaty of Berlin, signed on 13 July. It provided for a much smaller state, the Principality of Bulgaria, only comprising Moesia and the region of Sofia, and leaving large populations of ethnic Bulgarians outside the new country.[62][65] This significantly contributed to Bulgaria's militaristic foreign affairs approach during the first half of the 20th century.[66]

 

Borders of Bulgaria according to the preliminary Treaty of San Stefano

The Bulgarian principality won a war against Serbia and incorporated the semi-autonomous Ottoman territory of Eastern Rumelia in 1885, proclaiming itself an independent state on 5 October 1908.[67] In the years following independence, Bulgaria increasingly militarised and was often referred to as "the Balkan Prussia".[68] It became involved in three consecutive conflicts between 1912 and 1918—two Balkan Wars and World War I. After a disastrous defeat in the Second Balkan War, Bulgaria again found itself fighting on the losing side as a result of its alliance with the Central Powers in World War I. Despite fielding more than a quarter of its population in a 1,200,000-strong army[69][70] and achieving several decisive victories at Doiran and Monastir, the country capitulated in 1918. The war resulted in significant territorial losses and a total of 87,500 soldiers killed.[71] More than 253,000 refugees from the lost territories immigrated to Bulgaria from 1912 to 1929,[72] placing additional strain on the already ruined national economy.[73]

 

Tsar Boris III

The resulting political unrest led to the establishment of a royal authoritarian dictatorship by Tsar Boris III (1918–1943). Bulgaria entered World War II in 1941 as a member of the Axis but declined to participate in Operation Barbarossa and saved its Jewish population from deportation to concentration camps.[74] The sudden death of Boris III in mid-1943 pushed the country into political turmoil as the war turned against Germany, and the communist guerrilla movement gained momentum. The government of Bogdan Filov subsequently failed to achieve peace with the Allies. Bulgaria did not comply with Soviet demands to expel German forces from its territory, resulting in a declaration of war and an invasion by the USSR in September 1944.[75] The communist-dominated Fatherland Front took power, ended participation in the Axis and joined the Allied side until the war ended.[76] Bulgaria suffered little war damage and the Soviet Union demanded no reparations. But all wartime territorial gains, with the notable exception of Southern Dobrudzha, were lost.[77]

 

Georgi Dimitrov, leader of the Bulgarian Communist Party from 1946 to 1949

The left-wing coup d'état of 9 September 1944 led to the abolition of the monarchy and the executions of some 1,000–3,000 dissidents, war criminals, and members of the former royal elite.[78][79][80] But it was not until 1946 that a one-party people's republic was instituted following a referendum.[81] It fell into the Soviet sphere of influence under the leadership of Georgi Dimitrov (1946–1949), who established a repressive, rapidly industrialising Stalinist state.[77] By the mid-1950s, standards of living rose significantly and political repression eased.[82][83] The Soviet-style planned economy saw some experimental market-oriented policies emerging under Todor Zhivkov (1954–1989).[84] Compared to wartime levels, national GDP increased five-fold and per capita GDP quadrupled by the 1980s,[85] although severe debt spikes took place in 1960, 1977 and 1980.[86] Zhivkov's daughter Lyudmila bolstered national pride by promoting Bulgarian heritage, culture and arts worldwide.[87] Facing declining birth rates among the ethnic Bulgarian majority, Zhivkov's government in 1984 forced the minority ethnic Turks to adopt Slavic names in an attempt to erase their identity and assimilate them.[88] These policies resulted in the emigration of some 300,000 ethnic Turks to Turkey.[89][90]

The Communist Party was forced to give up its political monopoly on 10 November 1989 under the influence of the Revolutions of 1989. Zhivkov resigned and Bulgaria embarked on a transition to a parliamentary democracy.[91] The first free elections in June 1990 were won by the Communist Party, now rebranded as the Bulgarian Socialist Party.[92] A new constitution that provided for a relatively weak elected president and for a prime minister accountable to the legislature was adopted in July 1991.[93] The new system initially failed to improve living standards or create economic growth—the average quality of life and economic performance remained lower than under communism well into the early 2000s.[94] After 2001, economic, political and geopolitical conditions improved greatly,[95] and Bulgaria achieved high Human Development status in 2003.[96] It became a member of NATO in 2004[97] and participated in the War in Afghanistan. After several years of reforms, it joined the European Union and the single market in 2007, despite EU concerns over government corruption.[98] Bulgaria hosted the 2018 Presidency of the Council of the European Union at the National Palace of Culture in Sofia.[99]