Greek legends say that the Argonauts, led by Jason, sailed up the Bosporus past the site of Istanbul when they searched for the Golden Fleece. Long after the time of the legendary Argonauts, Greek adventurers founded a city called Byzantium (Buzantion, Byzas), in the early 500's B.C. This was the beginning of Istanbul.
In 513 B.C. the Persian king Darius I crossed the Bosporus at the point where Robert College now stands. He conquered the city of Byzantium and controlled it for a brief period. The city was captured in the 300's by Alexander the Great, King of Macedon, and finally came under Roman rule.
Byzantium was renamed in the A.D. 300's when Emperor Constantine I enlarged the city and made it the capital of his Eastern Empire. Constantine called the capital New Rome but it came to be known as Constantino-polis or the city of Constantine (in Greek). After the fall of Rome, Constantinople served as the capital of the Byzantine Empire for almost one thousand years.
The city was frequently attacked by hostile forces. It was captured by the armies of the Crusaders in 1203 and 1204. It withstood the attacks of the Turks until 1453, when Turkish forces overran Constantinople and brought an end to the Byzantine Empire.
From 1453 to 1922 Constantinople served as the capital of the Ottoman Empire. It was occypied by the Allies from the end of World War I until 1923. When Turkey became a republic in 1923 the capital was moved to Ankara.Instanbul was a center of activities for the agents of many countries during World War II because Turkey maintained strong neutrality.
Even though no longer the capital, Istanbul has retained its importance as a major trading center and strategically located city. It has remained the educational and cultural center of Turkey.