The Abbasid Caliphate (/əˈbæsəd/ or /ˈæbəsəd/ Arabic: الخلافة العباسية al-Khilāfah al-‘Abbāsīyah) was the third of the Islamic caliphates to succeed the Islamic prophet Muhammad. The Abbasid dynasty descended from Muhammad's youngest uncle, Abbas ibn Abd al-Muttalib (566–653 CE), from whom the dynasty takes its name. They ruled as caliphs, for most of their period from their capital in Baghdad in modern-day Iraq, after assuming authority over the Muslim empire from the Umayyads in 750 CE (132 AH).The Abbasid caliphate first centered its government in Kufa, but in 762 the caliph Al-Mansur founded the city of Baghdad, north of the Sasanian capital city of Ctesiphon. The choice of a capital so close to Persia proper reflected a growing reliance on Persian bureaucrats, most notably of the Barmakid family, to govern the territories conquered by Arab Muslims, as well as an increasing inclusion of non-Arab Muslims in the ummah. Despite this cooperation, the Abbasids of the 8th century were forced to cede authority over Al-Andalus and Maghreb to the Umayyads, Morocco to the Idrisid dynasty, Ifriqiya to the Aghlabids, and Egypt to the Shi'ite Caliphate of the Fatimids. The political power of the caliphs largely ended with the rise of the Buyids and the Seljuq Turks. Although Abbasid leadership over the vast Islamic empire was gradually reduced to a ceremonial religious function, the dynasty retained control over its Mesopotamian demesne. The capital city of Baghdad became a center of science, culture, philosophy and invention during the Golden Age of Islam.This period of cultural fruition ended in 1258 with the sack of Baghdad by the Mongols under Hulagu Khan. The Abbasid line of rulers, and Muslim culture in general, recentered themselves in the Mamluk capital of Cairo in 1261. Though lacking in political power, the dynasty continued to claim authority in religious matters until after the Ottoman conquest of Egypt (1517).