Praetorian prefect of the East

Praetorian prefecture of the East Praefectura praetorio Orientis Ἐπαρχότης τῶν πραιτωρίων τῆς ἀνατολῆς
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.
Capital		Constantinople
Historical era		Late Antiquity
•	Established	337
•	reorganization into themata	7th century
Political subdivisions		Diocese of Thrace Diocese of Asia Diocese of Pontus Diocese of the East Diocese of Egypt

The praetorian prefecture of the East or of Oriens (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 Oriens and Egypt.

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