The Arab city, the old or round city of Bagdad, was founded by the caliph Mansur of the Abbasid dynasty on the west side of the Tigris just north of the Isa canal in A.D.
917," in Journal Royal Asiatic Society, 1895, 1897; Baghdad under the Abbasid Caliphate (1901).
Damascus was taken by the Carmathians, and the name of the Abbasid caliph substituted for that of Moizz in public worship. IJasan al-A~am advanced from Damascus through Palestine to Egypt, encountering little resistance on the way; and in the autumn of 971 Jauhar found himself besieged in his new city.
Syria and Egypt next fell before him; he became master of the holy cities of Islam; and, most important of all, he induced the last Caliph of the Abbasid dynasty formally to surrender the title of caliph (q.v.), as well as its outward emblems, viz.
Its time of greatest prosperity and importance was the period of the Abbasid caliphate, and Arabic geographers as late as A.D.