Constantinople, a name rooted in Greek and Roman history, was called Istanbul by Turks for centuries. It was officially renamed in 1923. - sh.itjust.works

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.