Why is East Rome called Byzantium?

The name of Byzantium comes from an ancient Greek immigrant city near the sea. In 330 AD, the Roman emperor Constantine I built a city here as the capital of the Roman Empire and renamed it Constantinople. Constantinople, located in the Bosporus Strait, is a strategic waterway connecting the Black Sea and the Aegean Sea, and its geographical position is very advantageous. In 395 AD, the huge Roman Empire was invaded by barbarians from all walks of life. For the convenience of jurisdiction, the empire was divided into two parts. The Eastern Roman Empire took Constantinople as its capital, so it was also called the Byzantine Empire. The Byzantine Empire Territory of Macedonian Dynasty In 476 AD, the Western Roman Empire finally breathed its last breath after many invasions, including Xiongnu and many Germanic tribes. Byzantium became the only Roman Empire-in fact, they always claimed to be pure Roman descent.