 The Popes' status as elective monarchs turned the conclaves and consistories of the Renaissance into political battles between the courts of Italy for primacy in the peninsula and access to the immense resources of the Catholic Church.In 1439, Pope Eugenius IV and the Byzantine Emperor John VIII Palaiologos signed a reconciliation agreement between the Catholic Church and the Orthodox Church at the Council of Florence hosted by Cosimo "the old" de Medici.In 1453, Italian forces under Giovanni Giustiniani were sent by Pope Nicholas V to defend the Walls of Constantinople but the decisive battle was lost to the more advanced Turkish army equipped with cannons, and Byzantium fell to Sultan Mehmed II.