Caliph, the title adopted by the successors of Mahomet, as supreme in both civil and religious matters. The principal caliphates are: (1) the Caliphate of the East, established by Abubekr at Mecca, transferred to Bagdad by the Abassides (632-1258); (2) the Caliphate of Cordova, established at Cordova by Abderrahman (756-1031); (3) the Caliphate of Egypt, established by the Fatimites (909-1171). It was at Bagdad that Moslem civilisation achieved its final development.