What was the effect of the barbarian invasions on the Eastern Roman Empire?

The eastern Roman was known as Byzantium. Although it was attacked by the barbarians it was able to withstand the attacks from the barbarians because it was located on a strait and therefore it was difficult to break its defences. It had shorter common frontier with Europe, stronger administrative centre, internal political stability, sufficient manpower and great wealth which helped it to withstand the attacks. Thus the Byzantine Empire survived and continued as a Christian Capital for about a thousand years after the fall of Rome.