Praetorian prefecture of the East
Praefectura praetorio Orientis
Ἐπαρχότης τῶν πραιτωρίων τῆς Ανατολῆς
Ἑῴα Ὑπαρχία
Praet. Prefecture of the East Roman Empire
337–7th century

Praetorian Prefectures of the Roman Empire (395). The Praetorian Prefecture of the East is in grey.
Historical eraLate Antiquity
• Established
• Loss of Diocese of the East and Diocese of Egypt to the Rashidun Caliphate and reorganization into themata
7th century
Political subdivisionsDiocese of Thrace
Diocese of Asia
Diocese of Pontus
Diocese of the East
Diocese of Egypt

The praetorian prefecture of the East, or of the Orient (Latin: praefectura praetorio Orientis, Greek: ἐπαρχότης/ὑπαρχία τῶν πραιτωρίων τῆς ἀνατολῆς) was one of four large praetorian prefectures into which the Late Roman Empire was divided. As it comprised the larger part of the Eastern Roman Empire, and its seat was at Constantinople, the praetorian prefect was the second most powerful man in the East, after the Emperor, in essence serving as his first minister.


The Prefecture was established after the death of Constantine the Great in 337, when the empire was split up among his sons and Constantius II received the rule of the East, with a praetorian prefect as his chief aide. The part allotted to Constantius encompassed four (later five) dioceses, each in turn comprising several provinces. The authority of the prefecture stretched from the Eastern Balkans, grouped into the Diocese of Thrace, to Asia Minor, divided into the dioceses of Asiana and Pontus, and the Middle East, with the dioceses of Orient and Egypt.[1]

List of known praefecti praetorio Orientis


  1. ^ Palme 2007, p. 245.
  2. ^ PLRE I, Thalassius 1
  3. ^ Alan Cameron states that the first term of Aurelianus lasted until April 400
  4. ^ Cameron's dates for Aurelianus overlap those of Eutychianus in 400