Bolghar
The Bolghar are an Oghuric Turkic people of the middle Volga and Kama, heirs of Volga Bulgaria. After Old Great Bulgaria fell to the Khazars in 668, their ancestors reached the Volga in the eighth century and united the region from the late ninth century, with Bolghar as capital. In 922 Almış made Islam the state religion and received the caliph's envoy Ibn Fadlan; the country grew rich on the Volga trade.
Pressure from the princes of Vladimir forced the capital to Bilär, and in 1223 the Bulgars defeated a Mongol vanguard at Samara Bend. The Mongols returned in 1236 and subjugated the country, destroying much of its urban elite. Survivors became Golden Horde subjects; their towns were rebuilt as craft and caravan centres.
Through the fourteenth century they kept their Oghur tongue; by the 1430s their lands formed the Khanate of Kazan's core, and their language lived on among the Chuvash, last Oghuric people.