Other historians consider the Bakhtiyaris to have resided in their area for a long time, and that they named themselves after the ancient Persian word Bakhtar ("the West") due to their geographical position. Another theory supported by some historians is that the Bakhtiyaris are descended from Izz al-Dawla Bakhtiyar (r. 967–978), the Buyid ruler of Iraq. The name of the latter is first attestation of the word Bakhtiyar. The Bakhtiyaris themselves consider their name to be derived from the word Bakhtiyarwand, the name of the offspring of Bakhtiyar, a distinguished figure of Lur-i Buzurg (Greater Lur).