Establishment and Byzantium Period

The history of Istanbul began thousands of years ago. But, firstly, Megarians were the settlers in Istanbul in the 7th century B.C.E. Megaran was a city-state in Ancient Greece. Byzas, who was king of Megara, wanted to establish a new city-state, so he went to the Temple of Apollo and consulted an oracle. Oracle said that “you should establish against the country of the blind.” Byzas was confused. While he was walking, he looked at Kadiköy from Sarayburnu. He thought that while this area is more remarkable, why people founded a city there? Anyone, who founded a town there, must be blind. And he decided where to establish the city. And Megarians founded a city in 667 B.C.E. The city’s name was Byzantion. Byzantion is the first name before Constantinople and Istanbul.

Roman Empire Period of Constantinople 

Byzantion continued as an ordinary and unimportant city till C.E 4th Century. But Byzantion started to be important because of its location after Constantine became the emperor of the Roman Empire

Constantine was important to the history of Istanbul as Constantine considered moving the capital to another city. He considered Izmit, Troy, and Byzantion, and he chose Byzantion for it sat at the end of important trade routes. Also, Byzantion was built upon the land of seven hills like Rome. The city became the capital city 65 years ago before the Roman Empire separated. The city was mentioned as Constantinople after Constantine’s death. 

In the Constantine period, the city began to change and develop. Constantine didn’t ruin the city. He designated town borders. Constantine got the palace done for people who came from Milano. Hippodromes were built, and walls started to renew in ConstantinopleWe can say that the history of Istanbul was initiated in this period.

After Constantine’s death, the Emperors continued developing the city. During the Theodosius Period (379-395), he built a harbor to find a solution to the food problem. He got the warehouse done. Forum Tauri, now known as Beyazid Square, was built in this period. In 395, the Roman Empire was split into two parts East-Rome and Western-Rome. Western Rome’s capital city became Milano, and East- Rome’s capital city, was Constantinople. The city was built as a city for Christians after Emperor Theodosius signed the edict of Thessaloniki. In time, the city became the center of Christianity.

Constantinople continued to improve and change in the II. Theodosius Period. Walls extended and cultivated areas, structures were put under protection. In this time, Constantinople reached its most magnificent state. And the situation continued until the Roman Empire collapsed. In the 465 Emperor Leon period, a fire started in Constantinopleand it destroyed half of the city. After the fire, the city began to renew. But in Justinian I Period, Nika riots began, and the civil commotion ruined the city again. Justinian I suppressed Nika Riots, and he started to design new architecture, and he decided to build a new Church. The Church’s name was Hagia Sophia. He built the Basilica Cistern and the Binbirdirek Cistern. And he changed the official language to the Helen language. 

After Justinian I, the unproductive period started in the Roman Empire. But constructions started again in Constantinople in Theophilos and Basileios I Period. Churches, Monasteries were built in this period. Many of the buildings still are in Constantinople.

Latin Occupation

Constantinople was ruined during the crusades. In the Latins Occupation, the city was plundered. Intruders blasted many structures. And the city was burned in a planned way. 15.000 people, lived in Constantinople became homeless. For a while, the Latin Empire dominated the city.

In 1261, Mikhail Palaiologos VIII defeated the crusaders. And Constantinople returned to the old days. 

Roman Empire/ Byzantine After Latin Occupation

VII Mikhail Palaiologos won Constantinople again, but the city was fatigued and lost old magnificence because of the crusaders, fires, plunders, etc. When we look at the history of Istanbul in this period, the city was occupied by western states and Arabs. They had to struggle with these occupations. Although Constantinople came up against attacks, other states could not conquer the city until 1453.


Although other states occupied Constantinople, the city wasn’t conquered for centuries. But the history of Istanbul would be changed by the Turkish. The Ottoman Empire wanted to conquer ConstantinopleIn 1395, Bayezid I surrounded the city, but crusaders occupied the Balkans, and he had to recede. Bayezid I didn’t abandon this city. He got the Anatolian fortress done to ease this conquest. And in 1400, Bayezid I surrounded the city again, but Timur occupied Anatolia and Bayezid had to retreat again. I, Murad II wanted to conquer the city. And, in 1422, he surrounded the city, but Mustafa Riot prevented the conquest. The history of Istanbul started to change in 1453. The Ottoman Emperor Fatih Sultan Mehmet besieged the city, and he succeeded in his purpose. He conquered Constantinople, and the conquest caused the end of the Roman EmpireAfter the conquest, the city began to change. Hagia Sophia and other churches transformed into mosques. And the city became the capital of the Ottoman Empire. 

Frequently Asked Question

When did the Constantinople fall?
In 1453, when Mehmed the Conqueror seized it.
When was the Constantinople established?
In 330 AD.
What was the main religion of Constantinople?
Emperor Constantine made Christianity the main religion of Constantinople.