Constantinople, a name rooted in Greek and Roman history, was seen as representing the city’s imperial past before the rise of the Turkish nation-state. Istanbul, a name already used colloquially among Turks for centuries, became the official name. The government then encouraged and pressured foreign countries and mapmakers to adopt this new name as well.


Christians went to Greece and Moslems stayed in Turkei around the same time so maybe they wanted the split so it was more Turk in identity.