Question

Why was the Roman capital moved to Constantinople?

Answer 1

Emperor Constantine didn't move the capital per say, instead he split the empire in two and Constantinople became the capital of the Eastern Roman Empire.

Explanation:

Constantine believed that the Empire was simply too large to be managed as one entity, therefore he split it into two halves. The Western half and the eastern half now referred to as the Byzantine Empire. The western capital remained in Rome while the east got its new capital in the sprawling city of then called Byzantium but later got changed to Constantinople, after Constantine himself.

This split was more than just an organizational thing, they even had two separate emperors for the two halves and spoke different languages, Latin and Greek respectively.

Hope this helped :)