A city on the European shore at the mouth of the Thracian Bosporus. It was first established by Megarian colonists (c657 bc ). In the 6th century bc,
it came under Persian rule and then alternately under Spartan and Athenian rule in the 5th and 4th centuries. After its revolt from the second Athenian League (357), it was independent and became an ally of Rome at the time of the Third Macedonian War. It subsequently came under Roman rule and was chosen by Constantine the Great for his new capital; he renamed it Constantinople; now called Istanbul, it is a major city in Turkey.
Byzantium appears as a central symbol in the poetry of William Butler Yeats.
It occurs in " Sailing to Byzantium " and in " Byzantium, " where it represents the richness of an artistic civilization and the triumph of art over time and death.