Middle Ages

During the Middle Ages, Milan prospered as a centre of trade due to its command of the rich plain of the Po and routes from Italy across the Alps. The war of conquest by Frederick I Barbarossa against the Lombard cities brought the destruction of much of Milan in 1162. After the founding of the Lombard League in 1167, Milan took the leading role in this alliance. As a result of the independence that the Lombard cities gained in the Peace of Constance in 1183, Milan became a duchy. In 1395, Gian Galeazzo Visconti became duke of Milan. In 1450, Milan passed to the noble House of Sforza, which made Milan one of the leading cities of the Italian Renaissance.