The Byzantine Empire, also called the Eastern Roman Empire, was formed in 286 after the Roman Empire split apart.
Conflicts with the Cycaenaens
In 516, the Byzantines attempted to seize Cycaes, the capital of the Kingdom of Cycaenae. Their invasion was a total failure, and the draining of Byzantium's resources led to a reverse invasion. The Cycaenaens then invaded Byzantine lands throughout the rest of the 500s.