Bulan was a Khazar king who led the conversion of the Khazars to Judaism. His name means "elk" in Old Turkic. The date of his reign is unknown, as the date of the conversion is hotly disputed, though it is certain that Bulan reigned some time between the mid-700s and the mid-800s. Nor is it settled whether Bulan was the Bek or the Khagan of the Khazars. D.M. Dunlop was certain that Bulan was a Khagan; however, more recent works, … Wikipedia
The definitive Wikipedia entry for Bulan. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Bulan_%28Khazar%29