From Constantinople to Istanbul

A friend of mine asked me the other day about the cities of Constantinople and Istanbul. He wanted to know about the name change. I told him that the city was also called Byzantium. The early Greeks settled there and called their city Byzantium. The city kept this name from 657 BCE to 330 CE. The city was later taken over by the Romans and a later Roman Emperor, Constantine the Great changed the name of the city to Constantinople, in honor of himself. The city kept this name from 330 CE until 1453 CE. In 1453 the Ottoman Turks captured the city and yet again changed the name of the city to Istanbul and till this day the city is called Istanbul. So... I told my friend an easy way to remember all of the changes: Byzantium is Greek, Constantinople is Roman and Istanbul is Turkish. I have also found a couple of maps. One is a map of the Roman city of Constantinople and the second is of Istanbul in modern Turkey.