9.1.6 to 9.1.10

Muslim forces posed another threat. The armies of Suleyman the Magnificent, sultan of the Ottoman Turks, pressed up the Danube River into central Europe. Charles led a defense of Vienna in 1532 and later sailed to northern Africa to fight the Muslim pirates who raided his coast towns in Spain and Italy. Across the Atlantic Ocean, Charles's Spanish armies were conquering the rich empires of Mexico and Peru. In the 1550s, late in Charles's reign, gold and silver were brought back from the New World in large quantities. Charles was a devoted Roman Catholic but was unable to stop the great religious and social revolution, called the Reformation, that was started by the German monk Martin Luther. Luther's efforts to reform the Catholic church led to the establishment of Protestant forms of Christianity, including Lutheranism. Charles defeated a group of Protestant princes at M�hlberg in April 1547, but only eight years later he was forced to allow the Peace of Augsburg, which acknowledged the legitimacy of Lutheranism within the Holy Roman Empire. Charles had great military skill, which he demonstrated in both land warfare and naval expeditions. He also had great courage. Once when his aides rebuked him for exposing himself to danger, he replied, "We were short of men, and I could not set a bad example." In intervals of peace, he turned to forming alliances through royal marriages in order to stabilize his realm. He married Isabella, the daughter of the king of Portugal. He also arranged for his sister Mary to marry the king of Hungary, his brother Ferdinand to marry the sister of the Hungarian king, and his son Philip to marry the English queen Mary I. The last marriage failed to further Charles's cause as the English Parliament refused to crown a Catholic king.