Byzantium

noun3

1. •
   (historical) An ancient Greek city situated on the Bosporus in modern Turkey, renamed Constantinople in 330 C.E.; modern Istanbul.
2. •
   (historical) An ancient Greek empire in Southeastern Europe and Western Asia, with its capital at Constantinople; in full, Byzantine Empire.
3. •
   A dark shade of purple, close to Tyrian purple and palatinate purple.