Old Great Bulgaria
State · 633–681 CE · at its largest around 656 CE
A Bulgar state on the Pontic-Caspian steppe founded by Kubrat. Under Khazar pressure it broke up, and its groups moved to the Danube and the Volga.
On its lands while it lasted
- Chufut-Kale (500–1490 CE): Capital of Crimean Khanate (1450–1490).
More on Wikipedia.