Abbasid Caliphate

The Abbasid Caliphate or Abbasid Empire was the third Islamic caliphate, ruled by the Abbasid dynasty. The dynasty was descended from Muhammad's uncle, Abbas ibn Abd al-Muttalib (d. 653), after whom it is named. The Abbasids rose to power in 750, when the Abbasid Revolution overthrew the preceding Umayyad Caliphate, and they ruled as caliphs from their metropole in Iraq until 1258, with Baghdad as their capital for most of their history.

The Abbasid Revolution had its origins and first successes in the easterly region of Khurasan, far from the Levantine center of Umayyad influence. The Abbasids first centered their government in Kufa, Iraq, but in 762 the second caliph al-Mansur founded the city of Baghdad and made it the capital. Baghdad became a center of science, culture, arts, and invention, ushering in what became known as the Golden Age of Islam. It hosted several key academic institutions, such as the House of Wisdom, as well as a multi-ethnic and multi-religious population, which made the city famous as a centre of learning across the world. The Abbasid period was marked by the use of bureaucrats in government, including the vizier, as well as a growing inclusion of non-Arab Muslims in the ummah (Muslim community) and among the political elites.

The height of Abbasid power and prestige is traditionally associated with the reign of Harun al-Rashid (r. 786–809). After his death, a civil war brought new divisions and was followed by significant changes to the character of the state, including the creation of a new professional army recruited mainly from Turkic slaves and the construction of a new capital, Samarra, in 836. The 9th century also saw many provinces becoming increasingly autonomous, giving rise to local dynasties that controlled different regions of the empire, such as the Aghlabids, Tahirids, Samanids, Saffarids, and Tulunids. After a period of turmoil in the 860s, the caliphate regained some stability and its seat returned to Baghdad in 892.

During the 10th century, the caliphs were reduced to mere figureheads, with real political and military power resting in the hands of the Iranian Buyids and the Seljuq Turks, who took control of Baghdad in 945 and 1055, respectively. The Abbasids eventually regained control of Iraq during the reign of Caliph al-Muqtafi (r. 1136–1160) and extended their rule into Iran during the reign of Caliph al-Nasir (r. 1180–1225). This revival ended in 1258 with the sack of Baghdad by the Mongols under Hulagu Khan and the execution of Caliph al-Musta'sim, which marked the effective end of the Abbasid Caliphate. A surviving branch of the Abbasid dynasty was formally reinstated in 1261 by the Mamluk sultans in Cairo, but it lacked any political power. The dynasty continued to claim symbolic authority until the Ottoman conquest of Egypt in 1517, the last Abbasid caliph being al-Mutawakkil III.