Istanbul
Greek colonists from Megara established Byzantium on the Sarayburnu promontory around 657 BCE. These settlers built an acropolis adjacent to the Golden Horn, fueling the nascent city's economy with trade routes connecting Europe and Asia. Modern excavations have raised the possibility that the name Byzantium might reflect sites of native Thracian settlements that preceded the fully-fledged town. Pliny the Elder mentioned a Thracian toponym Lygos as an earlier name for the site. The first human settlement on the Asian side, the Fikirtepe mound, dates from the Copper Age period between 5500 and 3500 BCE. Roman emperor Constantine the Great refounded the city in 324 CE and named it Nova Roma. Most people called it Constantinople, a name that persisted into the 20th century. On the 11th of May 330, Constantinople was proclaimed the capital of the Roman Empire. Turkish authorities began pressing for the use of Istanbul in foreign languages during the 1930s. The word Istanbul derives from the Medieval Greek phrase eis ten polin, literally meaning to the city. This reflected its status as the only major city in the vicinity. 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 occurred in 1730 during the reign of Sultan Mahmud I.
Constantine the Great effectively became the emperor of the whole of the Roman Empire in September 324. Two months later, he laid out plans for a new Christian city to replace Byzantium. During the following millennium of Roman history, the state was commonly referred to as the Byzantine Empire. Numerous churches were built across the city, including Hagia Sophia which remained the world's largest cathedral for a thousand years. Constantine also undertook a major renovation of the Hippodrome of Constantinople, accommodating tens of thousands of spectators. The city served as the capital of three empires over sixteen centuries: the Roman Empire, the Latin Empire, and the Ottoman Empire. The Fourth Crusade was diverted from its purpose in 1204, and the city was sacked by crusaders who established the Latin Empire. The Byzantine Empire was restored in 1261, albeit weakened. On the 29th of May 1453, after an 55-day siege, Sultan Mehmed II captured Constantinople. Hours after the fall of the city, the sultan rode to the Hagia Sophia and converted it into an imperial mosque. Mehmed declared himself as the new Kayser-i Rûm, the Ottoman Turkish equivalent of the Caesar of Rome. Following the capture, Mehmed II immediately set out to revitalize the city with massive restoration programs. He welcomed foreigners, criminals, and runaways, creating a cosmopolitan society that persisted through much of the Ottoman period. Suleiman the Magnificent's reign from 1520 to 1566 was a period of great artistic achievement. Chief architect Mimar Sinan designed several iconic buildings in the city during this era.
The Treaty of Lausanne was signed on the 24th of July 1923, ending the occupation of Constantinople. Turkish forces entered the city with a ceremony on the 6th of October 1923, marked annually as Liberation Day of Istanbul. On the 29th of October 1923, the Grand National Assembly of Turkey declared the establishment of the Turkish Republic with Ankara as its capital. Mustafa Kemal Atatürk became the Republic's first President. The overall population of Istanbul began to rapidly increase in the 1970s as people from Anatolia migrated to find employment in new factories. This sudden rise caused large demand for housing, engulfing previously outlying villages into the metropolitan area. As a result of exponential growth in the 20th century, significant portions of the city are composed of gecekondus, illegally constructed squatter buildings. Some gecekondu areas are being gradually demolished and replaced by modern mass-housing compounds. Large scale gentrification and urban renewal projects have taken place, such as those in Tarlabaşı and Sulukule. The Turkish government has ambitious plans for expansion west and northwards on the European side in conjunction with the new Istanbul Airport opened in 2019. The new parts will include four different settlements housing 1.5 million people. The population increased tenfold between 1950 and 2000, fueled by internal migration. People registered in Kastamonu, Ordu, Giresun, Erzurum, Samsun, Malatya, Trabzon, Sinop and Rize provinces represent the biggest population groups in Istanbul.
Istanbul straddles the Bosporus Strait, which provides the only passage from the Black Sea to the Mediterranean via the Sea of Marmara. Historically, the confluence of these waters provided ideal defense against enemy attack and a natural toll-gate. Several picturesque islands including Büyükada, Heybeliada, Burgazada, Kınalıada form part of the city. Istanbul's shoreline has grown beyond its natural limits through landfill operations. Despite the myth that seven hills make up the city, there are more than 50 hills within the city limits. Aydos is the tallest hill at high elevation. The North Anatolian Fault under the Sea of Marmara caused earthquakes in 1766 and 1894. A quake of at least magnitude 7.0 is very likely in the 21st century. Over half a million flats were still vulnerable to collapse as of recent assessments. On the 23rd of April 2025 an earthquake with preliminary magnitude of 6.2 shook the city. Many people suffered injuries while trying to jump from buildings or experienced panic attacks. The threat plays a large role in infrastructure development with over 500,000 vulnerable buildings demolished since 2012. Climate change has caused increases in heatwaves, droughts, storms, and flooding in Istanbul. Sea level rise threatens city infrastructure such as Kadıkoy metro station.
Istanbul had the eleventh-largest economy among world urban areas in 2018. It accounts for about thirty percent of Turkey's GDP and industrial output. Trade is economically important, accounting for significant portions of economic output in the city. In 2019, companies based in Istanbul produced exports worth billions and received imports totaling similar amounts. The Bosporus provides the only passage from Black Sea to Mediterranean, handling more than tons of oil each year. International conventions guarantee passage even when tankers carry flammable materials. Istanbul has been an international banking hub since the 1980s. Borsa Istanbul was originally established as the Ottoman Stock Exchange in 1866. In 1995, Borsa Istanbul moved its headquarters to İstinye near Maslak. Since 2023, the Ataşehir district on the Asian side hosts the Istanbul Financial Center where state-owned Turkish banks are located. As of 2023, five tallest skyscrapers in Turkey stand in Istanbul including CBRT Tower and Metropol Istanbul Tower. Foreign tourists visited the city in 2018, making it the fifth most-visited city globally that year. Istanbul expects one million tourists from cruise companies after renovation of Galataport in Karaköy district.
By the end of the 19th century, Istanbul had established itself as a regional artistic center with artists flocking to the city. When additional universities and art journals were founded during the 1980s, artists formerly based in Ankara moved in. Beyoğlu transformed into the artistic center with modern museums opening in the 2000s including İstanbul Modern and Pera Museum. The first film screening in Turkey occurred at Yıldız Palace in 1896. Movie theaters rapidly cropped up in Beyoğlu along İstiklal Avenue. Since then, Istanbul has been the most popular location to film Turkish dramas and comedies. The nation's movies began seeing substantial international success with films like Uzak in 2002 and My Father and My Son in 2005. Coinciding with cultural reemergence was establishment of the Istanbul Festival showcasing variety of art beginning in 1973. From this flagship festival came International Istanbul Film Festival and Istanbul Jazz Festival in early 1980s. The Istanbul Biennial held every two years since 1987 has risen in prestige alongside Venice Biennale. In 2024, Euromonitor International ranked Istanbul as second most visited city globally. The Grand Bazaar operates since 1461 among world's oldest covered markets. Galleria Ataköy ushered in age of modern shopping malls when it opened in 1987.
Common questions
When was Istanbul founded by Greek colonists from Megara?
Greek colonists from Megara established Byzantium on the Sarayburnu promontory around 657 BCE. Modern excavations suggest the name might reflect earlier Thracian settlements, and Pliny the Elder mentioned a Thracian toponym Lygos as an earlier name for the site.
Who refounded Constantinople and when did it become the capital of the Roman Empire?
Roman emperor Constantine the Great refounded the city in 324 CE and named it Nova Roma. On the 11th of May 330, Constantinople was proclaimed the capital of the Roman Empire after he effectively became emperor of the whole empire in September 324.
What happened to Istanbul on the 29th of May 1453 during the Ottoman conquest?
On the 29th of May 1453, Sultan Mehmed II captured Constantinople after a 55-day siege. Hours after the fall, the sultan converted Hagia Sophia into an imperial mosque and declared himself Kayser-i Rûm, the Ottoman Turkish equivalent of the Caesar of Rome.
When did the Turkish Republic declare Ankara its capital instead of Istanbul?
On the 29th of October 1923, the Grand National Assembly of Turkey declared the establishment of the Turkish Republic with Ankara as its capital. This followed the Treaty of Lausanne signed on the 24th of July 1923 which ended the occupation of Constantinople.
How many hills are there within the city limits of Istanbul today?
Despite the myth that seven hills make up the city, there are more than 50 hills within the city limits. Aydos is the tallest hill at high elevation, while the North Anatolian Fault under the Sea of Marmara has caused earthquakes in 1766 and 1894.