After the Fall of Constantinople, having conquered the Byzantine Empire, Mehmed took the title "Kayser-i Rûm", claiming succession to the Roman imperium. His claim was that, by possession of the city, he was emperor, a new dynast by conquest, as had been done previously by the likes of Heraclius and Leo III. Contemporary scholar George of Trebizond wrote "the seat of the Roman Empire is Constantinople ... and he who is and remains Emperor of the Romans is also the Emperor of the whole world".