Diocese of Egypt

This article is about Diocese of the Byzantine Empire. For an ecclesiastical diocese within the Province of Jerusalem and the Middle East (founded 1920), see Anglican Diocese of Egypt.

Diocese of Egypt Dioecesis Aegypti Διοίκησις Αἰγύπτου
Diocese of the Byzantine Empire
c. 380 – c. 642
The Diocese of Egypt c. 400.
Historical era	Late Antiquity
• Established	380
• Muslim conquest of Egypt	642
Preceded by Succeeded by Rashidun Empire Roman Egypt

The Diocese of Egypt (Template:Lang-la, Template:Lang-el) was a diocese of the later Roman Empire, incorporating the provinces of Egypt and Cyrenaica. Its capital was at Alexandria, and its governor had the unique title of praefectus augustalis (Augustal Prefect, of the rank vir spectabilis) instead of the ordinary vicarius. The diocese was initially part of the Diocese of the East, but in the year 370, it became a separate entity, which lasted until its territories were finally overrun by the Muslim conquest of Egypt in the 640s.

The diocese was included in the Praetorian prefecture of the East and included originally five provinces:

• Aegyptus Iovia, later renamed Aegyptus, comprised the western Nile Delta, and had Alexandria as its capital;
• Aegyptus Herculia, later renamed Augustamnica, comprised the eastern Delta, with Pelusium as capital;
• Thebais, which was bounded to the south by the First Cataract of the Nile, with Ptolemais Hermiou as capital;
• Libya Inferior (or Interior), corresponding to Marmarica, with Paraetonium as capital;
• Libya Superior (or Exterior), corresponding to Cyrenaica, with Ptolemais as capital.

Attributes Iovia and Herculia were related to the tetrarchs Diocletian and Maximian respectively, and were later changed to remove the pagan connotations.

By the early 6th century, the provinces had increased with the creation of:

• Aegyptus I
• Aegyptus II
• Augustamnica I, with Pelusium as capital;
• Augustamnica II
• Thebais Superior
• Thebais Inferior
• Arcadia, with capital Oxyrhyncus

During the reforms of Justinian I in the late 530s, the administrative structure changed again. The post of Augustal Prefect (vicar of the diocese) was abolished, and five independent governors (duces), who combined military and civilian authority, were appointed instead. Two of them, the dux Alexandriae and the dux Thebaidos also held the title augustalis (dux et augustalis).

List of Praefecti Augustalii

Taken from the Prosopography of the Later Roman Empire (except for Theognostus):

• Eutolmius Tatianus (367-370)
• Olympius Palladius (370-371)
• Aelius Palladius (371-374)
• Publius (c. 376)
• Bassianus (c. 379)
• Hadrianus (c. 379)
• Iulianus (c. 380)
• Antoninus (381-382)
• Palladius (382)
• Hypatius (383)
• Optatus (384)
• Florentius (384-386)
• Paulinus (386-387)
• Eusebius (387)
• Flavius Ulpius Erythrius (388)
• Alexander (388-390)
• Evagrius (391)
• Hypatius (392)
• Potamius (392)
• Orestes (415)
• Theognostus (c. 482)
• Petrus Marcellinus Felix Liberius (c. 539-542)