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.
Byzantine Empire under the Constantinian and Valentinian dynasties
Byzantium under the Constantinian and Valentinian dynasties was the earliest period of the Byzantine history that saw a shift in government from Rome in the west to Constantinople in the East within the Roman Empire under emperor Constantine the Great and his successors. Constantinople, formally named Nova Roma, was created on the site of the old Greek Byzantium, which is the origin of the historiographical name for the Eastern Empire, which self-identified simply as the "Roman Empire".