Answer:
Byzantium was it's first name, follwed by constantinople and finally Istanbul.
Step-by-step explanation:
First of all, let's locate ourselves geographically.
The islocated in the Bosporus strait connecting Europe and Asia. Between the sea of Marmara and the black sea. Now, it was the capital of the eastern Roman Empire and renamed constantinople for the greeks, then it became the capital of the ottoman empire and finally in 1923 when the ottoman empire became turkey the capital was moved to Ankara, and the city was renamed to Istanbul. What was Constantinople is today the historic center of Istanbul. And is located on the European side of the city.