Istanbul ( , ; ), formerly known as Constantinople, is the largest city in Turkey, serving as the country's economic, cultural and historic hub. The city straddles the Bosporus strait, lying in both Europe and Asia, and has a population of over 15 million residents, comprising 19% of the population of Turkey. Istanbul is the most populous European city and the world's 15th-largest city.
The city was founded as Byzantium (, ) in the 7th century BCE by Greek settlers from Megara. In 330 CE, the Roman emperor Constantine the Great made it his imperial capital, renaming it first as New Rome (, ; ) and then as Constantinople () after himself. In 1930, the city's name was officially changed to Istanbul, the Turkish rendering of (romanized: ; 'to the City'), the appellation Greek speakers used since the 11th century to colloquially refer to the city.
The city served as an imperial capital for almost 1600 years: during the Roman/Byzantine (330–1204), Latin (1204–1261), late Byzantine (1261–1453), and Ottoman (1453–1922) empires. The city grew in size and influence, eventually becoming a beacon of the Silk Road and one of the most important cities in history. The city played a key role in the advancement of Christianity during Roman/Byzantine times, hosting four of the first seven ecumenical councils before its transformation to an Islamic stronghold following the Fall of Constantinople in 1453 CE—especially after becoming the seat of the Ottoman Caliphate in 1517. In 1923, after the Turkish War of Independence, Ankara replaced the city as the capital of the newly formed Republic of Turkey.
Over foreign visitors came to Istanbul in 2018, eight years after it was named a European Capital of Culture, making it the world's eighth most visited city. The historic centre of Istanbul is a UNESCO World Heritage Site, and the city hosts the headquarters of numerous Turkish companies, accounting for more than thirty percent of the country's economy.
Toponymy
The first known name of the city is Byzantium (, ), the name given to it at its foundation by Megarian colonists around 657 BCE. Megarian colonists claimed a direct line back to the founders of the city, Byzas, the son of the god Poseidon and the nymph Ceroëssa. Modern excavations have raised the possibility that the name Byzantium might reflect the sites of native Thracian settlements that preceded the fully-fledged town. Constantinople comes from the Latin name Constantinus, after Constantine the Great, the Roman emperor who refounded the city in 324 CE. Constantinople remained the most common name for the city in the West until the 1930s, when Turkish authorities began to press for the use of "Istanbul" in foreign languages. () and were the names used alternatively by the Ottomans during their rule.
The name (, colloquial ) is commonly held to derive from the Medieval Greek phrase (pronounced ), which means "to the city" and is how Constantinople was referred to by the local Greeks. This reflected its status as the only major city in the vicinity. The importance of Constantinople in the Ottoman world was also reflected by its nickname meaning the 'Gate to Prosperity' in Ottoman Turkish. An alternative view is that the name evolved directly from the name Constantinople, with the first and third syllables dropped. Some Ottoman sources of the 17th century, such as Evliya Çelebi, describe it as the common Turkish name of the time; between the late 17th and late 18th centuries, it was also in official use. The first use of the word () on coinage was in 1730 during the reign of Sultan Mahmud I. In modern Turkish, the name is written as , with a dotted İ, as the Turkish alphabet distinguishes between a dotted and dotless I. In English the stress is on the first or last syllable, but in Turkish it is on the second syllable (). A person from the city is an (plural: ); Istanbulite is used in English.
History
Neolithic artifacts, uncovered by archeologists at the beginning of the 21st century, indicate that Istanbul's historic peninsula was settled as far back as the 6th millennium BCE. That early settlement, important in the spread of the Neolithic Revolution from the Near East to Europe, lasted for almost a millennium before being inundated by rising water levels. The first human settlement on the Asian side, the Fikirtepe mound, is from the Copper Age period, with artifacts dating from 5500 to 3500 BCE, On the European side, near the point of the peninsula (Sarayburnu), there was a Thracian settlement during the early 1st millennium BCE. Modern authors have linked it to the Thracian toponym Lygos, mentioned by Pliny the Elder as an earlier name for the site of Byzantium.