This chapter identifies a comparative context for the Roman Empire in the Muslim imperial experience, from the Caliphate to the Mughals and Ottomans. As Crone once noted, the Caliphate was founded by Arab conquerors, but was quickly taken over by provincial converts to Islam in a process that saw the consolidation of an imperial monarchy, a court society, and garrisoned army. The course of Roman history mirrors this story of provincial takeover. A coalition of Italian conquerors expanded across the Mediterranean. Consolidation of conquests happened in a revolution that saw the institutionalization of a monarchy, the formation of a court, and a standing army. Only a little more slowly than in the Arab case, the history of the monarchy evolved as provincials came increasingly to constitute the personnel of the empire. At the end, power abandoned the city of Rome, only to find a durable seat in Constantinople on the Bosporus.