Constantinople
Constantinople (Roman name: Constantinopolis; Greek: Konstantinoupolis or Κωνσταντινούπολη) is the former name of the city of Istanbul in Turkey. Its original name was Byzantium (Greek Bυζαντιον, transliterated as Byzantion).
"Constantinople" is an Anglicization of Konstantinoupolis, which means "City of Constantine." The name is a reference to the Roman emperor Constantine I who made it the capital of the Roman Empire on May 11, 330 AD. Constantine named the Nova Roma (New Rome), but that name never came into common use.
Constantinople was the capital of the Eastern Roman Empire, also known as as the Byzantine Empire. It was captured and sacked by the Fourth Crusade in 1204 and then re-captured by Nicaean forces under the command of Michael VIII Palaeologus in 1261.
Constantinople and the Byzantine Empire finally fell to the Ottoman Empire on May 29, 1453 (See the Fall of Constantinople). In Ottoman times, both the names Constantinople and Istanbul were used, although westerners invariably called the city Constantinople. Istanbul only became the official name in 1930. When the Republic of Turkey was founded in 1923, the capital was moved from Istanbul to Ankara.
In Byzantine times the Greeks called Constantinople i Poli ("the City"), since it was the centre of the Greek world and for most of the Byzantine period the largest city in Europe. The name Istanbul is a Turkish rendering of Constantinople. The belief that it comes from the Greek phrase eis tin Poli ("to the City") is a piece of folk etymology.