The First Bulgarian Empire (Bulgarian: Първо Българско царство, Parvo Balgarsko Tsarstvo), was the first country of the contemporary Bulgarian people located in Southeastern Europe. Since its foundation it occupied a large part of the Balkan peninsula and struggled with the Byzantine Empire for control of the region.
Founded as a crude form of a confederacy between Bulgars, Slavs and Thracians in 681 on the two banks of the Danube river, it became the first Slavic country and is the oldest state still in existence in Europe. In 802-805 it destroyed the Avar Khanate and expanded its territory twice covering the whole area of contemporary Romania. During the 9th and the beginning of the 10th century in the course of the Byzantine-Bulgarian Wars the Bulgarians took control of most of the Balkans. However in the mid 10th century the Empire suffered disastrous invasions of Magyars, Pechenegs and wars with Kievan Rus' and after a 50-year struggle it was destroyed by the Byzantines in 1018.
After the Christianization of Bulgaria the country became a major center of culture and learning. Literature flourished in the Preslav and Ohrid Literary Schools. The Bulgarian scholar Climent of Ohrid (840 - 916), who was a student of Saints Cyril and Methodius, invented the Cyrillic alphabet which carries the name of one of his teachers. The beauty and wealth of the new capital Preslav was compared by some contemporaries with Constantinople. In the 10th century in Bulgaria emerged one of the major heretic movements in Medieval Europe, the Bogomils.
The Second Bulgarian Empire (Bulgarian: Второ българско царство, Vtorо Bălgarskо Tsartsvo) was established in 1185 as a result of the Uprising of Asen and Peter and reached the peak of its power under Kaloyan and Ivan Asen II before gradually being conquered by the Ottomans in the late 14th and early 15th centuries.
Up until 1256, the Second Bulgarian Empire was the dominant power in the Balkans. The Byzantines were defeated in several major battles, and in 1205 the newly-established Latin Empire was crushed in the battle of Adrianople by Emperor Kaloyan. His nephew, Ivan Asen II (r. 1218–1241), defeated the Despotate of Epiros and made Bulgaria a regional power once again. However, in the late 13th century the Empire declined under the constant invasions of Tatars, Byzantines, Hungarians, Serbs, and internal instability and revolts.
The capital Tarnovo became a major cultural, religious and literary center during 13th and 14th centuries and was considered by some as the Third Rome for a time. During the rule of Ivan Alexander (1331-1371) Bulgaria experienced its Second Golden Age.