Constantinople
Constantinople (; ) was the capital city of the Roman/Byzantine Empire (330–1204 and 1261–1453), and also of the brief Crusader state known as the Latin Empire (1204–1261), until finally falling to the Ottoman Empire (1453–1923). It was reinaugurated in 324 from ancient Byzantium as the new capital of the Roman Empire by Emperor Constantine the Great, after whom it was named, and dedicated on 11 May 330. The city was located in what is now the European side and the core of modern Istanbul.
Treaty of Constantinople (1800)
The negotiations and mutual rivalties between Russia, the Porte, and the Islanders, led to the signing of the Treaty of Constantinople on 21 March 1800, which created the first autonomous Greek state since the Fall of the Byzantine Empire.