After the League of Cognac failed, Francis concluded a secret alliance with the Landgrave of Hesse on 27 January 1534. This was directed against Charles V on the pretext of assisting the Duke of Württemberg to regain his traditional seat, from which Charles had removed him in 1519. Francis also obtained the help of the Ottoman Empire and after the death of Francesco II Sforza, ruler of Milan, renewed the contest in Italy in the Italian War of 1536–1538. This round of fighting, which had little result, was ended by the Truce of Nice. The agreement collapsed, however, which led to Francis' final attempt on Italy in the Italian War of 1542–1546. This time Francis managed to hold off the forces of Charles V and Henry VIII. Charles V was forced to sign the Treaty of Crépy because of his financial difficulties and conflicts with the Schmalkaldic League.