What effect did Constantine's movement of the roman capital have?
Constantine the Great moved the capital of the eastern part of the Roman Empire from Nicodemia (in northwestern Turkey) to nearby Byzantium, which he redeveloped and turned it into the capital of this part of the empire in 330 and renamed it Constantinople.
Emperor Diocletian had created two imperial capitals in 286. Nicomedia was turned to the imperial capital of the eastern part of the Roman Empire and was his seat. Milan, in Italy, was turned into the imperial capital of the western part of the Roman Empire and was the seat of Diocletian's co-emperor, Maximian. Diocletian created a co-emperorship to improve the defence of the vast frontiers of the Roman Empire which were under constant attack. He designated the mentioned cities as imperial capitals because they were closer to the frontiers to be defended than Rome. Rome became only the nominal capital of the whole empire. Co-emperorship in itself was nothing new. It had occurred several times previously.
Constantine started as a co-emperor under the arrangement created by Diocletian. When he became sole emperor after winning two civil wars, he decided to move the capital of the eastern part of the empire. The creation of a new capital for the east in itself was not a massive change, because this part of the empire already had a capital. It is not clear exactly why he did this. One thing which is quite certain is that it was at least partly a propaganda exercise. Constantine was good at propaganda. He even created a fictitious ancestry from a previous emperor. A new capital built by him was a showcase of the new dawn for the Roman Empire which his sole rule would usher in. The city was named after him (Constantinople means city of Constantine) and was given honorary titles such as "Roma Constantiniana," "The Eastern Rome" the "New, Second Rome" and "Alma Roma."
It has been suggested that Constantine wanted to build a Christian capital, but this is doubtful. It is not even sure whether he actually converted to Christianity He supported Christianity, and promoted its development, but continued to worship the Apollo-Sun god and asked both pagans and Christians to observe the day of the sun, which was devoted to this god. He also remained the head of the Roman state religion. It is said that he got baptised before his death, but this is not absolutely certain. He built important churches in Constantinople (the Church of the Holy Apostles and the Hagia Eirene) and elsewhere: The old Basilica of St Peter's in Rome (centuries later in fell in disrepair and was replaced by the current one) the Papal Archbasilica of St John's Lateran (which was Rome's cathedral and the original residence of the popes) and the Church of the Holy Sepulchre in Jerusalem,
