In order to compensate for the weakening of the provinces and to maintain the link between the Imperial centre and the individual provinces, the dioceses were created as a new territorial subdivision above the level of the province. The empire was divided into twelve dioceses. The largest of these, the Diocese of the East, encompassed sixteen provinces. Each diocese was governed by an "agens vices praefectorum praetorio" (Acting Representatives of the Praetorian Prefects) or simply Vicar ("vicarius"), under the Praetorian prefect, although some provinces were governed directly by the Praetorian Prefect. These vicars had previously been ad hoc representatives of the prefects, but they were now made into permanent, regularised positions. The vicar controlled the provincial governors (variously titled as "consulares", "correctores", "praesides") and heard appeals of cases decided at the provincial level (parties could decide whether to appeal to the vicar or the praetorian prefect). The provinces governed by proconsuls (Africa and Asia) remained outside the vicars' jurisdiction. as did the cities of Rome and Constantinople, which were governed by a "Praefectus urbi" instead. The vicars had no military powers. Troops stationed in the dioceses fell under the command of a "comes rei militaris", who was directly under the control of the "magister militum" and was in charge of the "duces" who had the military command of individual provinces.