This city's name was changed to Constantinople in honor of Constantine.

Byzantium

Istanbul

Rome

Byzantium's name was changed to Constantinople in honor of Constantine. Once emperor Constantine conquered this city, he decided to name it after himself and changed it to Constantinople. Today, this city is known as Istanbul, one of the largest cities in Turkey. Rome is located in another country, so that is definitely not the correct answer. First the city was named Byzantium, then Constantinople, and today Istanbul.