Constantinoples name was changed to after the ottomans defeated it in 1453

Costantinople's name was changed to Istanbul after the Ottomans defeated it in 1453.

Explanation:

Constantinople is the historical name of the current city of Istanbul, located on both sides of the Bosphorus Strait in Turkey, and which was the capital of various empires throughout history: the Roman Empire (330-395), the Eastern Roman Empire or the Byzantine Empire (395-1204 and 1261-1453), the Latin Empire (1204-1261) and of the Ottoman Empire (1453-1922), which renamed it as Istanbul.

the western roman empire flourished, but the eastern portion of the empire struggled.

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