The beginning of the Middle Ages is considered to be the year 476, the dethronement of Romulus Augustulus - the last Western Roman emperor. The exact date for the end of the Middle Ages is not clear. Some consider its end in the conquest of Constantinople by the Turks in 1453, others in the first expedition of Christopher Columbus to America in 1492, and still others in the beginnings of the Reformation movement in 1517.