The origin of theand their homeland are still subjects of research generating many hypothesis and violent disputes. Bulgars, also called, were one of the three ethnic ancestors of modern Bulgarians (the other two were Thracians and Slavs ). They were mentioned for the first time in 354 AD by Anonymous Roman Chronograph as people living north of the Caucasus mountain and west of the Volga River . Headed by their chieftan Vund, Bulgars invaded Europe with the Huns about 370 AD, [0] and retreating with the Huns about 460 AD they resettled in the area north and east of the Sea of Azov