The ‘Abbasid Dynasty (r. 750–1258) came to power after a revolution (747–750) that resulted in the overthrowing of the Syrian-based Umayyad dynasty (r. 661–750). Scholars have divided the period of ‘Abbasid rule into two main eras: (1) 750–945, the ‘‘Golden Age’’ of ‘Abbasid rule and the beginning of its decline; and (2) 945–1258, the period after the ‘Abbasids’ loss of autonomy to regional warlord dynasties and ending with the Mongol execution of the last ‘Abbasid caliph in 1258. This division, which islargelyartificialinnature,hasaffectedthenatureof the modern study of the ‘Abbasids, with the majority of work being done on the earlier period of ‘Abbasid rule.