Volga Bulgaria was a state in modern-day southwestern Russia, formed by the descendants of a group of Bulgars distinct from those who under Asparuh crossed the Danube river and formed the First Bulgarian Empire (c. 680–1018). The Volga Bulgarians were for much of their early history, until the tenth century, under the suzerainty of the Khazar Khaganate.
No medieval records from Volga Bulgaria itself have survived; its history is instead a reconstruction largely based on information drawn from contemporary Russian, Arabic and Persian sources. According to later legend, the founder of Volga Bulgaria was the 7th-century ruler Kotrag, a son of Kubrat, though modern historians consider his historicity doubtful. The process of unification and state formation in Volga Bulgaria appears to have begun at some point in the late 9th century; Volga Bulgaria emerges from obscurity in the sources in the early 10th century, already a state of some size.
In the early tenth century, the Volga Bulgarian ruler Almış converted to Islam and worked to achieve independence from the Khazars; by 950, Volga Bulgaria was a fully independent state. The conversion to Islam helped the Volga Bulgarian rulers to distance themselves both from the Khazars (which followed Judaism) and the Byzantine Empire (which followed Christianity and was allied with the Khazars). Volga Bulgaria endured until it was conquered by the Mongol Empire in 1236.
List of rulers.
The former territories of Volga Bulgaria were integrated into the Mongol Empire in 1236 and later became part of the lands of the Golden Horde. After the collapse of Mongol rule in the region, much of the old Volga Bulgarian state became part of the new Khanate of Kazan (1438–1552), which in many ways was a continuation of Volga Bulgaria. The rulers of the Khanate of Kazan are listed in the separate "list of Kazan khans". After Kazan was conquered by Russia in 1552, Russian rulers sometimes adopted the title "Prince of Bulgharia", in reference to Volga Bulgaria.