Theodosius II – Gibbon’s Decline and Fall of the Roman Empire Chapter 32 Part 4
There are plenty of options to choose from for dating the start of the Byzantine Empire. But if you wanted one that would stand up in court, the reign of Arcadius is a pretty sound bet. The great Theodosius I was the last emperor to rule both halves of the empire unambiguously. He divided his inheritance between his two sons with Arcadius taking the eastern half, and as it turned out that court was to have a more or less continuous history from that point, the year 395, until the final end of the empire.
