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.
Probus (emperor)
According to the favorable treatment of Gibbon (whose account is largely derived from the "Augustan History"), Probus was the last of the benevolent constitutional emperors of Rome. While his successor Carus (Imp. 281-284) simply disdained to seek the senate's confirmation of his title, the latter's successor Diocletian (Imp. 284-305) took active measures to undermine its authority, and established the autocratic nature and divine deriviation of the Imperial power. Never again, after Diocletian's reforms, would the Roman senate play an active role in the management of the empire. On the military sphere, Probus' victories continued the succession of martial Illyrian emperors begun by Claudius Gothicus, which restored the military supremacy of Rome after defeats sustained during the crisis of the third century.Attribution: