<P> Byzantium or Byzantion (/ bɪˈzæntiəm, bɪˈzænʃəm /; Greek: Βυζάντιον, Byzántion) was an ancient Greek colony in early antiquity that later became Constantinople, and later Istanbul . Byzantium was colonized by the Greeks from Megara in c. 657 BC . </P> <P> The etymology of Byzantion is unknown . It has been suggested that the name is of Thraco - Illyrian origin . It may be derived from a Thracian or Illyrian personal name, Byzas . Ancient Greek legend refers to a king Byzas, the leader of the Megarian colonists and founder of the city . The form Byzantium is a Latinisation of the original name . Much later, the name Byzantium became common in the West to refer to the Eastern Roman Empire, the "Byzantine" Empire, whose capital Constantinople stood on the site of ancient Byzantium . This usage was introduced only in 1555 by the historian Hieronymus Wolf, a century after the empire had ceased to exist . During the time of the empire, the term Byzantium was restricted to just the city, rather than the empire it ruled . </P>

The old greek city-state of byzantium was rebuilt and became known as