What part of the roman empire became known as the byzanine empire

The Byzantine Empire, also referred to as the Eastern Roman Empire and Byzantium, was the continuation of the Roman Empire in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantinople (modern-day Fatih, İstanbul, and formerly Byzantium).

The Byzantine Empire, also referred to as the Eastern Roman Empire and Byzantium, was the continuation of the Roman Empire in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantinople (modern-day Fatih, İstanbul, and formerly Byzantium).

While the Western Roman Empire fell in 476 AD, the Byzantine Empire in the East lasted another 1,000 years. Its people never called themselves “Byzantines”; they considered themselves Rhomaioi, or Romans, and they traced their history back to the beginning of the Roman Empire.

i don't know why don't you google it?