Constantine had altogether more ambitious plans. Having restored the unity of the empire, he was overseeing the progress of major governmental reforms and sponsoring the consolidation of the Christian church, and became well aware that Rome had become an unsatisfactory capital for several reasons. Rome lay too far from the eastern imperial frontiers, and hence also from the armies and the Imperial courts (emperors had long before abandoned administering the empire from Rome); it offered an undesirable playground for disaffected politicians; it suffered regularly from flooding and from malaria. Yet it had been the capital of the state for over a thousand years, and it seemed unthinkable to suggest that that capital be moved.

Nevertheless, Constantine identified the site of Byzantium as the correct place: a city where an emperor could sit, readily defended, with easy access to the Danube or the Euphrates frontiers, his court supplied from the rich gardens and sophisticated workshops of Roman Asia, his treasuries filled by the wealthiest provinces of the empire.

Good Luck!!!

Instability in Rome, it was sacked by the Goths in 420AD. Constantinople was considered more defensible than Rome. First the Goths sacked it, then the Huns, and after that there wans’t much left behind to defend. It always required importing lots of grain to work, and the mechanism for brining in the grain was never very defensible. Constantinople was closer to major trade and water routes, and was easier to supply and defend until 1453.

Essentially, when the Germanic tribes sacked Rome, the Empire was split into two separate locations. Constantinople then developed its own distinct cultural identity.

It was because of the emperor Constantine and his conversion to Christianity. The most beautiful church the Hagia Sophia was built there and you can still see it today in Turkey but it is a mosque now. Although they are restoring the original Christian mosaics in it.

the empire was divided into two, and they had political and economic problems