Prefetture regionali, prefetture ministeriali

The major change in the history of the praetorian prefecture is the multiplication of the praetorian prefects and their transformation into civil officials. External to the court, they administer the so-called regional praetorian prefectures. Today, some historians see this transformation as a long progressive phenomenon. The latter attribute the genesis of such a process of regionalisation to Constantine’s desire to place a praetorian prefect alongside his young Caesars. According to this thesis, up until the late 4th century AD, there were still praetorian prefects who were bound to individual emperors. While these were installed in the court – the so-called ‘ministerial prefects’ – there were other praetorian prefects who were sent out to administer regional prefectures – the so-called ‘regional prefects’. This reconstruction is untenable. The evidence suggests that the praetorian prefecture from Constantine onwards was exclusively regional.