|View of Constantinople by Moonlight by Ivan Aivazovsky (1846)|
In the year 330, the city of Byzantium was renamed Nova Roma by the emperor Constantine. It soon became known as Constantinople, the city of Constantine. The "new Rome" became the Imperial capitol and reflected the prioritization of Roman interests, from the Latin West to the Greek East.
With Imperial resources focused eastward, the West faced an inexorable decline. Within 150 years of the new orientation, the Western Empire collapsed in 476 with the ousting of Romulus Augustulus by the Germanic chieftain Odoacer. However, the Eastern Empire survived as the Byzantine Empire until the Ottoman Turks took Constantinople in 1453. It wasn't always pretty, but the City of Constantine was made to endure.
With the founding of the Republic of Turkey in 1923, the city was officially renamed Istanbul, a name which had been informally used for centuries. Of all the names the city has had, I like the sound of Istanbul most. However, the Thracian name, Lygos, from around the 12th century BC, has a nice sound to it. ;-)
Here are the Wikipedia links to Byzantium, Constantinople, and Istanbul.
Here's Ivan Aivazovsky's Wikipedia page.