Konstantinos XI Palaiologos was the final reigning emperor of the Byzantine Empire, holding the throne from 1449 until 1453. Born in Constantinople to Emperor Manuel II and the Serbian noble Helena Dragaš, he was a skilled military leader who previously served as the Despot of the Morea. His reign was defined by efforts to secure Western military aid through church union and the desperate defense of his capital against the Ottoman Empire. He died in battle during the fall of Constantinople, marking the end of the Eastern Roman Empire.