Batbayan-Bezmer was placed in charge of the Bolgars by Chouvrtou but was overthrown in 677. He retreated to Carpathia consolidating his rule around Cuzdrioara , Ungvar and Halych where he paid tribute to the Turks of Azov. He seems to have been descended from the Aba clan making him the ancestor of Bulan. He and his descendants after him remained loyal to the Kara-Khazars converted to Judaism under Bulan whose descendants were the Kiabar-Cozars in Kopyriv Kinets'.