Constantinople, Stamboul, Islambol; It often depended on what time of the Middle Ages and what language you spoke.

istanbul = Turkish name

stamboul = old french name/spelling. they now spell it as is Turkish

In A.D. 330, Constantine established the city that would make its mark in the ancient world as Constantinople, but also would become known by other names, including the Queen of Cities, Istinpolin, Stamboul and Istanbul.

Istanbul - Not Constantinople - was created in 1953.

Constantinople