History

Sometime between 330 and 350 AD (likely c. 341), the Roman province of Euphratensis was created out of the territory of Coele Syria along the western bank of the Euphrates.^[1] It included the territories of Commagene and Cyrrhestice. Its capital was Cyrrus^[2] or perhaps Hierapolis Bambyce.^[1] It remained within the Byzantine Empire following the 395 division of the empire by Theodosius I.

The province is listed in the Laterculus Veronensis from around 314.

The Roman Catholic and Orthodox saints Sergius and Bacchus were supposedly martyred in the city of Resafa in Euphratensis, and the city was later renamed Sergiopolis. Other cities in the province were Samosata and Zeugma.

References

^ ^a ^b Kazhdan, Alexander, ed. (1991). Oxford Dictionary of Byzantium. Oxford University Press. p. 748. ISBN 978-0-19-504652-6.
^ Edmund Spenser Bouchier, Syria as a Roman Province, 1916, p. 155

Late Roman and early Byzantine provinces (4th–7th centuries AD)

History

As found in the Notitia Dignitatum. Provincial administration reformed and dioceses established by Diocletian, c. 293. Permanent praetorian prefectures established after the death of Constantine I. Empire permanently partitioned after 395. Exarchates of Ravenna and Africa established after 584. After massive territorial losses in the 7th century, the remaining provinces were superseded by the theme system in c. 640–660, although in Asia Minor and parts of Greece they survived under the themes until the early 9th century.

Western Roman Empire (395–476)

Praetorian prefecture
of Gaul

Diocese of Gaul	Alpes Poeninae et Graiae Belgica I Belgica II Germania I Germania II Lugdunensis I Lugdunensis II Lugdunensis III Lugdunensis IV Maxima Sequanorum
Diocese of Vienne¹	Alpes Maritimae Aquitanica I Aquitanica II Narbonensis I Narbonensis II Novempopulania Viennensis
Diocese of Spain	Baetica Balearica Carthaginensis Gallaecia Lusitania Mauretania Tingitana Tarraconensis
Diocese of the Britains	Britannia I Britannia II Flavia Caesariensis Maxima Caesariensis Valentia (?)

Praetorian prefecture
of Italy

Diocese of Suburbicarian Italy	Apulia et Calabria Campania Corsica Lucania et Bruttii Picenum Suburbicarium Samnium Sardinia Sicilia Tuscia et Umbria Valeria
Diocese of Annonarian Italy	Alpes Cottiae Flaminia et Picenum Annonarium Liguria et Aemilia Raetia I Raetia II Venetia et Histria
Diocese of Africa²	Africa proconsularis (Zeugitana) Byzacena Mauretania Caesariensis Mauretania Sitifensis Numidia (divided as Cirtensis and Militiana during the Tetrarchy) Tripolitania (Roman province)

Eastern Roman Empire (395–c. 640)

Praetorian prefecture
of Illyricum

Diocese of Pannonia³	Dalmatia Noricum mediterraneum Noricum ripense Pannonia I Pannonia II Savia Valeria ripensis
Diocese of Dacia	Dacia Mediterranea Dacia Ripensis Dardania Moesia I Praevalitana
Diocese of Macedonia	Achaea Creta Epirus Nova Epirus Vetus Macedonia Prima Macedonia II Salutaris Thessalia

Praetorian prefecture
of the East

Diocese of Thrace⁵	Europa Haemimontus Moesia II⁴ Rhodope Scythia⁴ Thracia
Diocese of Asia⁵	Asia Caria⁴ Hellespontus Islands⁴ Lycaonia (370) Lycia Lydia Pamphylia Pisidia Phrygia Pacatiana Phrygia Salutaris
Diocese of Pontus⁵	Armenia I⁵ Armenia II⁵ Armenia Maior⁵ Armenian Satrapies⁵ Armenia III (536) Armenia IV (536) Bithynia Cappadocia I⁵ Cappadocia II⁵ Galatia I⁵ Galatia II Salutaris⁵ Helenopontus⁵ Honorias⁵ Paphlagonia⁵ Pontus Polemoniacus⁵
Diocese of the East⁵	Arabia Cilicia I Cilicia II Cyprus⁴ Euphratensis Isauria Mesopotamia Osroene Palaestina I Palaestina II Palaestina III Salutaris Phoenice I Phoenice II Libanensis Syria I Syria II Salutaris Theodorias (528)
Diocese of Egypt⁵	Aegyptus I Aegyptus II Arcadia Augustamnica I Augustamnica II Libya Superior Libya Inferior Thebais Superior Thebais Inferior

Other territories
Taurica Quaestura exercitus (536) Spania (552)

¹ Later the Septem Provinciae
² Re-established after reconquest by the Eastern Empire in 534 as the separate Prefecture of Africa
³ Later the Diocese of Illyricum
⁴ Placed under the Quaestura exercitus in 536
⁵ Affected (i.e. boundaries modified, abolished or renamed) by Justinian I's administrative reorganization in 534–536