Why was constantinople chosen as the new roman capitol ?

Constantinople is the capital of the eastern Roman empire. What happened was Emperor Diocletian split up the Roman Empire into two parts, Western Roman Empire and Eastern Roman Empire because he felt that the Roman Empire was too big. Rome was the capital of the Western Roman Empire and Constantinople was chosen to be the capital of the Eastern Roman Empire. Constantinople was a fantastic location for trade because it was at the border between Europe and Asia so it was a rich city due to the trade.