On this day in 1930, the name of the city Constantinople was officially changed to Istanbul by Ataturk's government, which requested all countries to use the Turkish names for their cities
The renaming of cities in Turkey began in 1916 with Enver Pasha, one of the perpetrators of the Christian Genocides.
The names of around 12,000-14,000 villages were changed to Turkish names between 1916 and 1930 with successive governments.
Namely, that city had many names throughout history. The Ancient Greeks called the settlement located at that spot Byzantion (Βυζάντιον), while the Romans called it Byzantium.
Later, the name Constantinople (after the Roman emperor Constantine, who transferred the capital from Rome to there) became dominant.
That name stuck for most of the Middle Ages, i. e. during the time of the Byzantine Empire.
It is interesting that the Ottomans did not prefer the name Istanbul after they conquered the city.
Namely, the name Kostantiniyye, a variant of Constantinople, was dominant during the Ottoman period.
In Slavic languages, the city was called Carigrad or Tsarigrad (City of the Emperor), while the Vikings called it Mikligarðr (The Big City).
Today, Istanbul is one of the cities which had among the highest number of names throughout history.
The current Turkish government often insists on the name Istanbul instead of the older names which were used or are still in use in foreign countries