ABU AL-'ABBAS AS-SAFFAH

born , 722 died 754, Al-Anbar Islamic caliph (reigned 749-754), first of the 'Abbasid dynasty, which was to rule over eastern Islam for approximately the next 500 years. The 'Abbasids were descended from an uncle of Muhammad and were cousins to the ruling Umayyad dynasty. The Umayyads were weakened by decadence and an unclear line of succession, and they enjoyed little popular support, prompting the 'Abbasids to declare open revolt in 747. When Abu al-'Abbas assumed the caliphate in 749, he began a campaign of extermination against the Umayyads, the 'Alids, other 'Abbasid leaders who had become too popular, and all other claimants to power. He named himself as-Saffah, "the blood-shedder," because of his savage attacks. He established a firm legal and dynastic base for the 'Abbasids. His successor moved the caliphate to Baghdad.