The conventional legend of the city of Byzantium says that a Greek called Byzas from Megara founded Byzantium in 657 BC, when he sailed across the Aegean Sea. The legend also tells that the a sacred oracle told him to build the city on the European side, just oposite of the already established city of Chalcedon.
Most notable people from Byzantium are the tragedian Homerus, the engineer Philo, the astrologer Epigenes of Byzantium and the scholar Aristophanes of Byzantium.
Byzantium was a very prosperous city during many centuries mainly due to its position between the entrance of the Black Sea and Mediterranean Sea, and between Europe and Asia.
The end of Greek Byzantium was by the hand of Septimius Severus, a Roman Emperor. During the siege by Roman forces Byzantium suffered extreme damage. Byzantium was then rebuilt and renovated by Septimius Severus himself to quickly regain its previous development and prosperity.
The location of Byzantium attracted Roman Emperor Constantine I, and the city changed its name to Constantinople after his death in 330 AD. From noe on the city was the new capital of the Roman Empire.