Bulan was a descendant of Batbayan-Bezmer and the E-B405 Cozar. He was converted to Judaism by Yitzhak Sangari in 740 and took the name Sabriel. He made an alliance with Byzantium against Bulgaria and many of his men were buried in Chelarevo while helping Leo IV the Khazar. His descendants eventually joined the Kouver-Cozar secession as the Kiabar Jews of Kopyriv Kinets' who had split with the Kara-Khazars and assisted in the restoration of Hungary before being hung out to dry.