Constantinople comes from the Latin name Constantinus, after Constantine the Great, the Roman emperor who refounded the city in 324 CE. Modern excavations have raised the possibility that the name Byzantium might reflect the sites of native Thracian settlements that preceded the fully fledged town. Megaran colonists claimed a direct line back to the founders of the city, Byzas, the son of the god Poseidon and the nymph Ceroëssa. The first known name of the city is Byzantium ( Greek: Βυζάντιον, Byzántion), the name given to it at its foundation by Megarian colonists around 657 BCE. Istanbul is home to several UNESCO World Heritage Sites, and hosts the headquarters of numerous Turkish companies, accounting for more than thirty percent of the country's economy. Over 13.4 million foreign visitors came to Istanbul in 2018, eight years after it was named a European Capital of Culture, making the city the world's fifth-most popular tourist destination. In 1930, the city's name was officially changed to Istanbul, an appellation Greek speakers used since the eleventh century to colloquially refer to the city. In 1923, after the Turkish War of Independence, Ankara replaced the city as the capital of the newly formed Republic of Turkey. It was instrumental in the advancement of Christianity during Roman and Byzantine times, before its transformation to an Islamic stronghold following the Fall of Constantinople in 1453 CE. It served as an imperial capital for almost sixteen centuries, during the Roman/ Byzantine (330–1204), Latin (1204–1261), Byzantine (1261–1453), and Ottoman (1453–1922) empires. Istanbul is the most populous city in Europe, and the world's fifteenth-largest city.įounded as Byzantion by Megarian colonists in 657 BCE, and renamed by Constantine the Great first as New Rome ( Nova Roma) during the official dedication of the city as the new Roman capital in 330 CE, which he soon afterwards changed as Constantinople ( Constantinopolis), the city grew in size and influence, becoming a beacon of the Silk Road and one of the most important cities in history. The city straddles the Bosphorus strait, and lies in both Europe and Asia, with a population of over 15 million residents, comprising 19% of the population of Turkey. Istanbul ( / ˌ ɪ s t æ n ˈ b ʊ l/ IST-an- BUUL, US also / ˈ ɪ s t æ n b ʊ l/ IST-an-buul Turkish: İstanbul ( listen)) is the largest city in Turkey and the country's economic, cultural and historic center.