Explore the history of Istanbul from Byzantium to Constantinople, a city shaped by empires, religion, and iconic landmarks at the crossroads of Europe and Asia.
Istanbul is a living timeline where civilizations have risen, transformed, and left lasting marks on history. From its early days as Byzantium to its rebirth as Constantinople, the city has stood at the crossroads of Europe and Asia, shaping empires, religions, and cultures for centuries. Walking through Istanbul today, you can still feel the presence of these powerful eras in its streets, monuments, and skyline.
In this guide, I want to take you through the key moments that turned Istanbul into one of the most influential cities in the world. By exploring its journey from a Greek colony to the capital of the Roman and Byzantine Empires, you will better understand why Istanbul remains a unique historical and cultural treasure. This story is not only about the past, but also about how history continues to define the city we experience today.
Byzas sets out to find this country. When he comes to today's historical peninsula (Sultanahmet region), he sees that there is a settlement (Chalcedon) in the region where today's Kadıköy is located on the Anatolian side. When there is such a beautiful region, he is surprised that people set up settlements on the opposite shore. He thinks that the people living next to him are blind. What the oracle said comes to his mind and he establishes a colony in the region. This colony takes the name of the king and becomes Byzantion / Byzantium.
Byzantion remained an insignificant city until the 4th century AD. The fate of Byzantion changes when Constantine becomes Emperor in 312. Constantine's mother Helena is a good Christian. He constantly tells his son about Christianity and prays for him. Before Constantine's last battle during the throne fights, he started to look warmly to Christianity because of a vision he saw. He then signs the Edict of Milan, which will grant religious freedom to Christians. With this edict, the 300 years of persecution of Christians comes to an end, and this is one of Constantine's greatest achievements. Constantine has another big project. This project is to move the capital of the empire to another place. This is because Rome was vulnerable to barbarian raids from the north. In this direction, he thinks of Nicomedia, which is today's Izmit region, Troy and Byzantion, which is today's Istanbul. Constantine decides on Byzantion. One of the biggest reasons for deciding on Byzantion is the location of Byzantion. Being a peninsula due to the Sea of Marmara, the Bosphorus and the Golden Horn, consisting of seven hills like Rome, and its unique advantage in controlling trade routes, were effective in Constantine's decision. The fact that the city is open to growth, change and development is another motivation. Because instead of destroying the pagan heritage of Rome, there is a chance to build a new capital directly as a Christian city. Constantine moved the capital of the Roman Empire to Byzantion in 330 and named the city Nova Roma, that is, New Rome. After the death of Constantine, the city takes the name of Constantinople. Constantinople becomes the new capital of a new age.
Istanbul represents a new era at the end of the dark period that lasted for 300 years and Christians were constantly persecuted. Istanbul, which started with Constantine and became the capital of the Roman Empire under the rule of Christian Roman Emperors, becomes one of the most important cities in the history of Christianity. Today, the councils accepted as common by all Christians (Iznik Council, Chalcedon (Kadıköy) Council and Constantinople Council) were held during the period when Istanbul was the capital. During the reign of Emperor Theodosius, Christianity became the official religion of the Roman Empire with the Edict of Thessaloniki. The capital Constantinople, on the other hand, gradually turned into a center of Christianity. You can see many structures from the Roman Empire in Istanbul. The most important of these are the Aqueduct of Valens (AD 364), Hagia Sophia (AD 537), Basilica Cistern (532 AD), Hagia Eirene (537 AD), Galata Tower (528 AD).