The praetorian prefecture of Italy (Latin: praefectura praetorio Italiae, in its full form (until 356) praefectura praetorio Italiae, Illyrici et Africae) is one of four Praetorian prefectures into which the Late Roman Empire was divided.
It comprises the Italian peninsula, the Western Balkans, the Danubian provinces and parts of North Africa.
The Prefecture's seat moves from Rome to Milan and finally, Ravenna.The prefecture is established in the division of the Empire after the death of Constantine the Great in 337, and is divided into dioceses.
Initially these are the Diocese of Africa, the Diocese of Italy, the Diocese of Pannonia, the Diocese of Dacia and the Diocese of Macedonia (the last two had been until c. 327 united in the Diocese of Moesia).
Eventually the Diocese of Italy is split in two, the Diocese of Suburbicarian Italy (Italia suburbicaria: "Italy under the City", also referred to as "Diocese of the City of Rome") and the Diocese of Annonarian Italy (Italia annonaria: "provisioning Italy").In 356, the praetorian prefecture of Illyricum is established, comprising the dioceses of Pannonia, Dacia and Macedonia.
The new prefecture is abolished in 361 by Julian and reestablished in 375 by Gratian.
Its territory is contested between the two halves of the Empire, until the final partition in 395, when the Diocese of Pannonia is split off from the Illyricum and joined to the Western Empire and the prefecture of Italy as the Diocese of Illyricum.Despite the end of the Western Empire in 476, the Germanic successor states under Odoacer and Theodoric the Great continue to use the Roman administrative machinery, as well as being nominal subjects of the Eastern emperor at Constantinople.
The Prefecture thus survives, and comes again into Roman hands after Justinian's Gothic War.
However, with the Lombard invasion in 568, Roman rule becomes reduced to fragmented and isolated territories, and the Prefecture gives its place to the Exarchate of Ravenna, established by the emperor Maurice.Prefects continue however to be attested until well into the seventh century.
The last attested holder occurs in 639, and a couple of seals bearing the title eparchos ("prefect" in Greek) survive from the late seventh century, although it has been suggested that they are a misprint for exarchos ("exarch")
