Byzantium is an ancient Greek city, founded by Greek colonists from Megara in 657 BCE and named after their king Byzas.

The name Byzantium is a Latinization of the original name Byzantion.

The city is later renamed Nova Roma by Constantine the Great, but popularly called Constantinople and briefly becomes the imperial residence of the classical Roman Empire.

Subsequently the city is, for more than a thousand years, the capital of the Byzantine Empire, the Greek-speaking Roman Empire of late Antiquity and the Middle Ages.

Constantinople is captured by the Ottoman Turks, becoming the capital of their empire, in 1453.

The name of the city is officially changed to Istanbul in 1930 following the establishment of modern Turkey.The origins of Byzantium are shrouded in legend.

The traditional legend has it that Byzas from Megara (a town near Athens), founded Byzantium in 657 BCE, when he sailed northeast across the Aegean Sea.

Byzas had consulted the Oracle at Delphi to ask where to make his new city.

The Oracle told him to find it "opposite the blind."

At the time, he did not know what this meant.

But when he came upon the Bosporus he understood: on the opposite eastern shore was a Greek city, Chalcedon, whose founders were said to have overlooked the superior location only 3 kilometers (1.9 mi) away.

Byzas founds his city here on the European coast and names it Byzantion after himself.

It is mainly a trading city due to its location at the Black Sea's only entrance.

Byzantion later conquers Chalcedon, across the Bosporus on the Asiatic side.