OBADIAH, king of the Khazars, a descendant of Būlān, and collateral ancestor of *Joseph according to the Reply of Joseph (see *Khazars). Obadiah is mentioned in the correspondence as a reformer in Khazaria who "renewed the state, established the [Jewish] religion, built synagogues and colleges, sent for many of the wise men of Israel and gave them much silver and gold, and they explained to him the books of the Bible, Mishnah and Talmud, and the whole liturgy" (Reply, short version). This reform probably took place in about 800 C.E., i.e., about the time when, according to Masʿūdī (Murūj al-Dhahab, vol. 2, 8–9), the Khazar king accepted Judaism (see *Būlān).
D.M. Dunlop, History of the Jewish Khazars (1954), 144, 148; M.I. Artamonov, Istoriya Khazar (1962), 278–80.