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.
Roman Republic
Since the foundation of Rome, its rulers had been monarchs, elected for life by the patrician noblemen who made up the Roman Senate. The last Roman king was Lucius Tarquinius Superbus ("Tarquin the Proud"). In the traditional histories, Tarquin was expelled in 509 because his son, Sextus Tarquinius, had raped the noblewoman Lucretia, who afterwards took her own life. Lucretia's father; her husband, Lucius Tarquinius Collatinus; and Tarquin's own nephew, Lucius Junius Brutus, mustered support from the Senate and army, and forced Tarquin into exile in Etruria.