The history of Istanbul is, in many ways, the story of where East meets West. For nearly 2,700 years this city has stood at the meeting point of Europe and Asia, and it has been the capital of three of the greatest empires in history: the Roman, the Byzantine and the Ottoman.
Byzantium: the beginnings (657 BC)
According to tradition, it all began around 657 BC, when a Greek settler named Byzas founded a colony on the headland at the mouth of the Golden Horn, where Topkapı Palace stands today. The site was strategic: it controlled the crossing between Europe and Asia and the sea route between the Mediterranean and the Black Sea. He named it Byzantion, better known today by its Latin name, Byzantium.
Constantinople: the New Rome (AD 330)
In AD 330 the Roman emperor Constantine I moved the capital of the Roman Empire to Byzantium and renamed it Constantinople. He gave it new walls, palaces and its first Christian churches, and enlarged the Hippodrome. For the best part of a thousand years it was the richest and most populous city in Europe.
The Byzantine era (330–1453)
For more than a thousand years Constantinople was the heart of the Byzantine Empire. Its greatest architectural achievement is Hagia Sophia, built under Justinian and completed in 537. With a dome some 31 metres across, it was the largest cathedral in the world for almost a thousand years. The Theodosian Walls, built under Theodosius II in the 5th century, protected the city through dozens of sieges.
The Ottoman conquest (1453)
On 29 May 1453 Sultan Mehmed II, “the Conqueror”, took Constantinople after a 53-day siege. He was only 21. He turned Hagia Sophia into a mosque, built Topkapı Palace and opened the city to people of every faith and culture. Istanbul became the capital of the Ottoman Empire.
The Ottoman golden age (15th–17th centuries)
Under sultans such as Suleiman the Magnificent, whose chief architect was Mimar Sinan, Istanbul filled with some of the finest mosques in the Islamic world, among them the Süleymaniye and the Şehzade Mosque (Sinan’s own masterpiece, the Selimiye, is in Edirne). The Grand Bazaar grew into one of the largest covered markets in the world, with 61 covered streets and around 4,000 shops.
The Republic of Türkiye (1923)
Mustafa Kemal Atatürk founded the Republic of Türkiye in 1923 and made Ankara its capital. Istanbul lost its role as the political capital, but it has never stopped being the economic and cultural heart of the country. Hagia Sophia was made a museum by a decree of 1934 (it opened as one in 1935) and became a mosque again in 2020.
Istanbul today
With around 16 million inhabitants, Istanbul is a megacity that balances tradition and modernity: skyscrapers alongside Ottoman mosques, contemporary art galleries a short walk from centuries-old bazaars, and a historical legacy that few cities in the world can match.
To really understand the history of Istanbul, you need a guide who can tell you the stories behind every stone. Book a private tour of Istanbul with an English-speaking guide.