Byzantium is an ancient city located in modern-day Turkey. It was founded in 667 BC and was the capital of the Byzantine Empire from 330 AD until its fall in 1453. The city is now known as Istanbul, which is an 8 letter word that is a solution to the crossword. William Butler Yeats was an Irish poet who wrote a poem about the city of Byzantium in 1928, which is a 5 letter word that is also a solution to the crossword.