(d. 755) Leader of a revolutionary movement in Khorāsān whose efforts brought down the Umayyad dynasty .
Born into the mawālī (non-Arab Muslim) class and of humble origins, he met an agent of the ʽAbbāsid family while in prison (741). After his arranged release, he was sent to Khorāsān (745–746) to instigate a revolt. Recruiting from various discontented groups, he succeeded in overthrowing the last Umayyad caliph, Marwān II (750), and was rewarded with the governorship of Khorāsān. His popularity led the second ʽAbbāsid caliph, al-Manṣūr, to view him as a threat and have him put to death. See also Abbāsid dynasty .