First Bulgarian Empire

The First Bulgarian Empire was a medieval state in southeastern and south-central Europe, lasting from the 7th into the 11th century. It began in 680–681 when a Bulgar group under Asparuh moved into the northeastern Balkans. After defeating a Byzantine army led by Constantine IV—possibly with aid from local South Slavic tribes—they gained Byzantine recognition and the right to settle south of the Danube. At its peak in the 9th and 10th centuries, the empire stretched from the Danube Bend to the Black Sea and from the Dnieper River to the Adriatic Sea, making it a major power that could rival Byzantium.

As Bulgaria became established in the Balkans, it had a long, mixed relationship with the Byzantine Empire—sometimes allied, often at war. It became Byzantium’s main northern threat, leading to many conflicts, but there were also peaceful periods, such as during the Second Arab Siege of Constantinople, when a Bulgarian army broke the siege and destroyed the Arab force, preventing an invasion of southeastern Europe. Byzantine culture strongly influenced Bulgaria, which eventually adopted Christianity in 864. After the Avar Khaganate collapsed, Bulgaria expanded northwest into the Pannonian Plain. Later, the Bulgarians fought off Pechenegs and Cumans and decisively defeated the Magyars, forcing them to settle permanently in Pannonia.

Over time, the ruling Bulgars and other non-Slavic groups mixed with the Slavic majority and adopted their language, forming the Bulgarian nation between the 7th and 10th centuries. By the 10th century, the term “Bulgarian” became the standard name for the local people in both writing and speech. The development of Old Church Slavonic helped prevent the South Slavs from being absorbed into neighboring cultures and created a distinct Bulgarian identity.

After adopting Christianity, Bulgaria became the leading cultural and spiritual center of Slavic Europe. This status grew with the adoption of the Glagolitic alphabet and the creation of the Early Cyrillic alphabet in the capital Preslav. Old Church Slavonic literature spread north, making the language a common tongue across much of Eastern Europe. In 927, the Bulgarian Patriarchate was officially recognized as independent.

In the late 9th and early 10th centuries, Simeon I won many battles against the Byzantines. He was recognized as tsar (caesar) and expanded the empire to its largest size. After destroying a Byzantine army at the Battle of Anchialus in 917, the Bulgarians besieged Constantinople in 923 and 924, but failed and retreated. Between 967 and 969, the Kievan Rus prince Sviatoslav I Igorevich invaded, turning the empire into a Rus vassal. After Sviatoslav was killed in 972, Bulgaria briefly recovered but could not regain lands north of the Danube, in Thrace, or southern Macedonia. The Byzantines eventually struck back. In 1014, at the Battle of Kleidion, Emperor Basil II (called “the Bulgar Slayer”) crushed the Bulgarian army and ordered 15,000 prisoners blinded—every 100th soldier kept one eye to lead the rest home, forcing their families to support them. By 1018, the last Bulgarian strongholds surrendered, ending the First Bulgarian Empire. It was succeeded by the Second Bulgarian Empire in 1185.

The state was known simply as Bulgaria after Byzantine recognition in 681. Historians sometimes call it Danube Bulgaria, the First Bulgarian State, or the First Bulgarian Tsardom. From 681 to 864, it is also called the Bulgarian Khanate or Bulgar Khaganate, after the Turkic title of its rulers, and specifically the Danube Bulgarian Khanate to distinguish it from Volga Bulgaria. After Christianization in 864 and the adoption of Old Church Slavonic as the official language in 893, its rulers used the imperial title Tsar (first in 913), so the country is also called the Tsardom of Bulgaria. In English, it is often referred to as the Bulgarian Empire.

In antiquity, the eastern Balkans were home to Thracian Indo-European tribes. The region up to the Danube was gradually incorporated into the Roman Empire by the 1st century AD. After the 3rd century, the Roman decline and invasions by Goths and Huns left much of the area devastated and depopulated by the 5th century. The surviving eastern half, the Byzantine Empire, could only control coastal areas and some inland cities, though it never gave up its claim to the whole region up to the Danube. Reforms improved things somewhat, but disorder continued across much of the Balkans.