. "The Khanate of Great Bulgaria was the main power in the Russian steppe from 605-620. It was destroyed by the Khazars in 620 and was succeeded by the Danube Bulgar Khanate of the Danube estuary."@en . "Khanate of Great Bulgaria (Yarmuk)"@en . "The Khanate of Great Bulgaria was the main power in the Russian steppe from 605-620. It was destroyed by the Khazars in 620 and was succeeded by the Danube Bulgar Khanate of the Danube estuary."@en . .