What are all the capitals of the Roman Empires?

Answer 1

First of all, regarding the use of the word empires: there was only one Roman Empire. The emperor Diocletian created new administrative subdivisions on top of the provinces, which he reduced in size and doubled in number. These were 12 dioceses and four praetorian prefectures. He also created the tetrarchy (rule by four) where the empire was ruled by two senior emperors (Augusti, Diocletian and Maximian) and two junior emperors (Caesars, Galerius and Constantius Chorus),with each in charge of one of the four praetorian prefectures. Diocletian was in charge on the eastern part of the empire and the praetorian prefecture Oriens (the East, the Middle East, Egypt and Thrace - south-eastern Bulgaria and north-eastern Greece). Maximian was in charge of the east and the praetorian prefecture of Italia et Africa. Galerius was in charge of the praetorian prefecture of Illyricum (the Balkan Peninsula except for Thrace). Constantius Chlorus was in charge of the Praetorian prefecture of Galliae (Hispania, Gaul and Britannia).

Diocletian also designated four imperial capitals: Nicomedia (modern Izmit, in north-western Turkey) for Oriens, Mediolanum (modern Milan in northern Italy) for Italia et Africa), Sirmium(modern Sremska Mitrovica, in Serbia) for Illyricum, and Augusta Treverorum (modern Trier, in Germany). Rome had already ceased to be the political pivot of the empire because it was far from the troubled frontiers of the empire and many of the emperors in the third century were military men not connected with the city of Rome).

When Constantine the Great became the sole emperor after winning two civil wars, he created his own imperial capital. He redeveloped Byzantium and renamed it Constantinople. The Valentinian dynasty created a co-emperorship with one emperor in charge of the east and one of the easts. Constantinople remained the capital in the east and Milan remained the capital in the west. In 402 the capital in the east was moved from Milan to Ravenna.

Terms such as Western Roman Empire and Eastern Roman Empire have been coined by historians. The Romans did not use them