In July 1535 he was part of the naval troops reconquering the city of Tunis in North Africa. The failure on the third war against France trying to invade Provence, and the death of the first Governor of the Duchy of Milan, Antonio de Leyva, prompted him in 1538 to accept the nomination as governor, replacing Marino Caracciolo, the second governor, becoming some sort of protector of literary and musical people [clarification needed]. Wars with French and North Italians ended for a while with the Treaty of Crespy (1544). He also became a Knight in the Order of the Golden Fleece.