After the foundation of Chalcedona, Apollo is said to have enjoined the founders of Byzantium, in answer to their inquiries, to build their city opposite to the Blind, applying this name to the Chalcedonians, who, even though they were the first persons to arrive in these parts, did not take possession of the opposite side, which afforded such great resources of wealth, and chose the barren coast.
Strabo, Geographica, 7.6.2

Around 660 B.C., colonists from Megara, following a prophecy from the Oracle of Delphi, began a journey to settle on the opposite side of the city of the blinds. These were the previous Megarian colonists who, a few years before, chose to found their city, Chalcedona, on the opposite shore. The name of this new city, Byzantion, which was built on the head of the triangular peninsula between the Golden Horn, Bosporus and Propontis (Sea of Marmara), derives, according to the legend, from the Thracian-born king Byzas.

From the 6th till the 4th century B.C., Byzantion has known periods of Persian and Spartan dominion, has participated in the First and Second Athenian League and was sieged unsuccessfully by Philip II (340/339 B.C.). In 196 B.C. it was conquered and destroyed by the Roman emperor Septimius Severus (193-211 B.C.) and eventually it was downgraded to a small town (kome). Soon enough though, it regained its rights as a city under the name of Antonina.

The transformation of Byzantion to Constantinople was made by Constantine I (324-337), starting with the rebuilding processes in 324 and officially consecrated on 11 May 330. Immediately after its foundation, the city was characterized as Second Rome and later New Rome. Indeed Constantinople was to become the capital of the Eastern part of the Roman Empire. The term Byzantine Empire which is used till today, was only introduced in the 16th century by the German humanist Hieronymus Wolf (1516-1580) in his work Corpus Historiae Byzantinae (1557).

Three Ecumenical Councils and many regional were convened in Constantinople, which also serves as the seat of the Ecumenical Patriarchate.

The population growth, the increase of wealth and its buildings were remarkable. From the Notitia Urbis Constantinopolitanae (425), we are informed about the division of the city in 14 regions and for the large number of public, private and religious monuments, the colonnaded streets along with the most important one, the Mese, and for the public and private baths. Between 408 and 413, the extension of the land walls by 1.5 kilometer to the west of the Constantinian walls was made by Theodosius II (408-450) and in 439 the sea walls were completed.

The city was harmed in 532 by Nika Riots, in 542 by the plague and in 618 by the Arab conquest of Egypt, with the immediate loss of its major source of grain. Later, it was sieged by the Avaro-Slavs (626) and the Arabs (674-678 from the sea and 717-718), eventually without being conquered. In the 11th and 12th century, great economic and cultural growth occurred, which was accompanied by the construction of large monastic complexes with imperial funds. A great part of Constantinople was damaged in the Fire of August 1203, while in 1204 Crusaders captured and plundered the city. When in August 1261 Michael VIII Palaiologos (1259-1282) entered the regained by the Byzantines city, he had to combat the desolation and the devastation caused during the Latin occupation.
After the brief period of prosperity in the first decades of 14th century, abandonment followed, as it is reflected in the travelers’ texts. After its Fall to the Ottoman Turks in 1453, Constantinople became the capital of the establishing Ottoman empire. Although Ankara was made the capital city of the Republic of Turkey in 1923, Constantinople (officially renamed to Istanbul in 1930), remains the most populous city of modern Turkey and a big cultural and financial center.