 Byzantine emperor Maurice in 585 AD created the province of ""Mauretania Prima"" and erased the old Mauretania Sitifensis.Indeed, the emperor Maurice in that year created the office of "Exarch", which combined the supreme civil authority of a praetorian prefect and the military authority of a "magister militum", and enjoyed considerable autonomy from Constantinople.Two exarchates were established, one in Italy, with seat at Ravenna (hence known as the Exarchate of Ravenna), and one in Africa, based at Carthage and including all imperial possessions in the Western Mediterranean.