For 15 years, the League existed without opposition because Charles was busy fighting wars with France and the
Ottoman Empire. Overall, the
Ottoman–Habsburg Wars lasted from 1526 to 1571. In 1535,
Francis I of France, despite vigorously persecuting Protestants at home, supported the Protestant princes in their struggle against their common foe, Charles. The tactical support ended in 1544 with the signing of the
Treaty of Crépy in which the French king, who was fighting the Emperor in Italy, pledged to stop backing the Protestant princes and the League in Germany. In 1535, Charles led the
Conquest of Tunis. Francis, in an effort to limit the power of the Habsburgs, allied with
Suleiman the Magnificent of the
Ottoman Empire and formed a
Franco-Ottoman alliance. The
Italian War of 1536–38 between France and the Holy Roman Empire ended in 1538 with the
Truce of Nice. The final war during that period Charles fought against France, the
Italian War of 1542–46, ended with inconclusive results and the
Treaty of Crépy.. After the peace with France, Charles signed the
Truce of Adrianople in 1547 with the Ottoman Empire, which was allied to Francis, to free even more Habsburg resources for a final confrontation with the League. ==Schmalkaldic War==