Istanbul or Istamboula, officially called thus from 1930 and historically Byzantium and Constantinople, is the largest city and metropolis of Turkey and the prefecture of the homonymous province, of which it represents approximately 50% of the surface but more than 97% of the population. Four historic areas of the city have been on the UNESCO World Heritage List since 1985. Istanbul is the main economic center (financial, commercial and industrial center) of Turkey but also the cultural capital of the country.
Istanbul is the largest city in the country. The population of the entire Istanbul conurbation is estimated at 15 million inhabitants in 20142,3 which makes it one of the largest urban areas in the world. With an important cultural and historical heritage, the cosmopolitan city is a hotspot for tourism.
Located on the edge of the Marmara Sea and on either side of the Bosphorus Strait — therefore, according to certain political approaches (see Limits of Europe), straddling two continents, Europe and Asia — Istanbul is generally considered the gateway to Europe because the historic city is located on the western shore of the strait.
Officially called İstanbul since March 28, 1930, it has had other names throughout its history (still sometimes used depending on the context), notably Byzantium at the time of its foundation, then Constantinople (from May 11, 330 in honor of the Roman Emperor Constantine I).
Founded as Byzantion, the city can look back on 2,600 years of history. Also called the “Second Rome”, Istanbul belonged first to Thrace, then to the Roman Empire, of which it was the second capital after 395, (which became the Eastern Roman Empire and was called the “Byzantine” in the sixteenth century by Hieronymus Wolfe), then to the Ottoman Empire since May 29, 1453, and finally, just after its fall on August 10, 1920, to the Republic of Turkey, of which it was the capital until October 13, 1923, when this administrative function was transferred to Ankara. The old names of the city, Byzantium then Constantinople, testify to this long history. Only a few other major cities have had three names in their history. From the historical point of view, it is possible to consider that with Athens and Rome, Constantinople is one of the three most important ancient capitals. As the seat of the Ecumenical Patriarchate and — until 1924 — the Ottoman Caliphate, Istanbul was also an important center of Orthodox Christianity and Sunni Islam for centuries.
The inhabitants of ancient Byzantium were called Byzantiotes and those of Constantinople, Constantinopolitans or Politainians. On the other hand, no citizen of the Eastern Roman Empire was ever called Byzantine: they defined themselves as “Romans” and when they became subjects of the Ottoman Empire, it organized them into the Milliyet of Rum. The inhabitants of Istanbul are known as Stambouliotes or Istanbuliotesf.