Praetorian prefecture of Italy

The Praetorian Prefecture of Italy (Latin: Praefectura Praetorio Italiae, Greek: Υπαρχία της Ιταλίας) was one of four large Praetorian prefectures into which the Late Roman Empire was divided. It comprised the Italian peninsula, the Western Balkans, the Danubian provinces and parts of North Africa. The Prefecture's seat was either Rome or, in later times, Ravenna.

Structure and history

The Prefecture was established by Constantine the Great in 318, and was divided into dioceses. Initially these were two, the Diocese of Africa and the Diocese of Italy. Eventually the latter was split in two, the Diocese of Italia suburbicaria and the Diocese of Italia annonaria. In the course of the 4th century, the Praetorian prefecture of Illyricum changed hands between the Eastern and Western Empire. With the final partition in 395, the Diocese of Pannonia was split off from the Prefecture and joined to the Western Empire and the Prefecture of Italy.

Despite the end of the Western Empire in 476, the Germanic successor states under Odoacer and Theodoric the Great continued to use the Roman administrative machinery, as well as being nominal subjects of the Eastern emperor at Constantinople. The Prefecture thus survived, and came again into Roman hands after Justinian's Gothic War. However, with the Lombard invasion in 568, Roman rule became reduced to fragmented and isolated territories, and the Prefecture gave its place to the Exarchate of Ravenna, established by the emperor Maurice.

Prefects

Flavius Taurus (355-361)
Rufus Synesius Hadrianus (400-405)
Longinianus (?-408)
Caecialianus (409)
Jovius (409)
Rufus Synesius Hadrianus (413-416)
Anicius Acilius Glabrio Faustus (ca. 438)
Liberius (494-500)
Cassiodorus the Elder (500-?)
Faustus (507-512)
Cassiodorus the Younger (533-ca. 537)

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 After massive territorial losses in the 7th century, the remaining provinces were superseded by the theme system in c. 640–660, although in Asia Minor and parts of Greece they survived under the themes until the early 9th century.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 Bruttium 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