This study was created on the basis of a wide range of early medieval Arab-Persian, Khazar-Jewish, Old Russian, Scandinavian, Byzantine and Western European sources with the involvement of modern domestic and foreign historiographic experience. The monograph offered to the attention of readers is the result of a detailed scientific study of the political and ethnosocial situation of the Alano-Bulgarian population of the Khazar Khaganate in Podonye-Pridonechye at the end of the 7th - 10th centuries.