History of Europe
In 395 Theodosius I, who had made Christianity the official religion of the Roman Empire, would be the last emperor to preside over a united Roman Empire. The empire was split into two halves: the Western Roman Empire centred in Ravenna, and the Eastern Roman Empire (later to be referred to as the Byzantine Empire) centred in Constantinople. The Roman Empire was repeatedly attacked by Hunnic, Germanic, Slavic and other “barbarian” tribes (see: Migration Period), and in 476 finally the Western part fell to the Heruli chieftain Odoacer.
Constantine XI Palaiologos
Constantine XI Dragases Palaiologos, Latinized as Palaeologus (, "Kōnstantinos XI Dragasēs Palaiologos"; 8 February 1405 – 29 May 1453) was the last reigning Roman and Byzantine Emperor, ruling as a member of the Palaiologos dynasty from 1449 to his death in battle at the fall of Constantinople in 1453.