When Charles's son
Philip inherited the duchy, Francis invaded Italy.
Philippe de Chabot, a French general, led his army into Piedmont in March 1536, and proceeded to capture Turin the following month, but he failed to seize the heavily fortified Milan. In response, Charles invaded
Provence, a region of France, advancing to
Aix-en-Provence, and took Aix in August 1536. His admirals
Andrea Doria and
Álvaro de Bazán the Elder similarly conquered cities through the coast of Provence, stopping only at
Marseille, which was too well defended and remained in control of its hinterland. Charles ultimately withdrew to Spain rather than attacking the heavily fortified
Avignon. There is also a story that French troops deliberately left over-ripe fruit on the trees in an attempt to give Charles's troops
dysentery. While Charles V was busy fighting for territory in France, Francis I's armies received massive reinforcements in Piedmont in terms of generals, troops, and horses on a march headed for Genoa. France had secured
an alliance with the
Ottoman Empire in 1536 through the diplomatic efforts of
Jean de La Forêt, France's ambassador to the Ottoman Empire. A Franco-Ottoman fleet under
Barbarossa was stationed in Marseille by the end of 1536, threatening
Genoa, by planning to attack simultaneously with the French troops marching on land towards the city. However, when they found out the defenses of the city had been recently reinforced, they elect to march instead onto Piedmont, capturing many towns there. In winter, Bazán the Elder routed another Franco-Ottoman fleet under Ali of
Algiers near
Collioure. In 1537 Barbarossa raided the Italian coast of Apulia as a preparation to a Franco-Ottoman land invasion of Naples, but the latter failed to materialize due to local resistance under Viceroy
Pedro de Toledo. Doria also scored a naval victory in
Antipaxos at the rear guard of the Ottoman armada. Barbarossa then laid a
laid a siege on the
Venetian colony of Corfu, although this provided only limited assistance to the French. With Charles V squeezed between the French invasion and the Ottomans, and Francis failing to advance in any side, the two ultimately made peace with the Truce of Nice on 18 June 1538.
Pope Paul III acted as a mediator, desiring to make peace between the warring Christians to launch a league against the Ottoman Empire. ==Truce of Nice==