The history of the new dynasty is marked by perpetual strife and the development of luxury and the liberal arts, in place of what their opponents identified as old-fashioned austerity of thought and manners. Mansur?, the second of the house, who transferred the seat of government to the new city of Baghdad, fought successfully against the peoples of Asia Minor, and the reigns of [Harun al-Rashid]? (786--809) and Mamun (813-833) were periods of extraordinary splendour. But the empire as a whole stagnated and then decayed rapidly. Independent monarchs established themselves in Africa and Khorasan (Spain had remained Umayyad throughout), and in the north-west the Greeks successfully encroached. The ruin of the dynasty came, however, from those Turkish slaves who were constituted as a royal bodyguard by Moqtasim (833-842). Their power steadily grew until Radi (934-941) was constrained to hand over most of the royal functions to Mahommed b. Raik. Province after province renounced the authority of the caliphs, who were merely lay figures, and finally Hulagu, the Mongol general, burned Baghdad (Feb. 28th, 1258). The Abbasids still maintained a feeble show of authority, confined to religious matters, in Egypt under the Mamelukes?, but the dynasty finally disappeared with Motawakkil III., who was carried away as a prisoner to Constantinople by Selim I.
see History of Islam