The title is of Iranian origin; scholars have derived it variously from the Old Iranian root "khshaeta", "shining, brilliant", or from "khshāyathiya", "ruler, king" (which is also the origin of the title "shah"). The Ikhshids of Soghdia, with their capital at Samarkand, are well attested during and after the Muslim conquest of Transoxiana. The line survived into Abbasid times, although by then its seat was in Istikhan. Among the most notable and energetic of the Soghdian kings was Gurak, who in 710 overthrew his predecessor Tarkhun and for almost thirty years, through shifting alliances, managed to preserve a precarious autonomy between the expanding Umayyad Caliphate and the Türgesh khaganate. The Arab authors report that the title was also used by the ruler of Ferghana during the same period: Ibn al-Athir reports that it was the "ikhshid" of Ferghana who called upon the Chinese for aid against the Arabs, resulting in the Battle of Talas.