A second exarchate was created by Maurice to administer northern Africa, formerly a separate praetorian prefecture, the islands of the western Mediterranean and the Byzantine possessions in Spain. The capital of the Exarchate of Africa was Carthage. An emperor of the Eastern Roman Empire, Heraclius, was the son of the exarch of Africa before Heraclius replaced the usurper emperor Phocas in 610. Phocas had revolted under emperor Maurice who had appointed Heraclius' father as exarch of Africa. The exarchate proved both financially and militarily strong, and survived until the Arab Muslim conquest of Carthage in 698.