For Charles’s honourable conduct on Luther’s appearance before the diet of Worms, the reader may refer to the life of the Reformer in our second volume. The cause of Lutheranism gained ground at the diet of Nuremberg; and if Charles had declared in favour of the Lutherans, all Germany would probably have changed its religion. As it was, the Reformation made progress during the war between the Emperor and Clement VII. All that Charles acquired from the diet of Spire in 1526, was to wait patiently for a general council, without encouraging novelties. In 1530, he assisted in person at the diet of Augsburg, when the Protestants (a name bestowed on the Reformers in consequence of the protest entered by the Elector of Saxony and others at the second diet of Spire) presented their confession, drawn up by Melancthon, the most moderate of Luther’s disciples. About this time Charles procured the election of his brother Ferdinand as king of the Romans, on the plea that, in his absence, the empire required a powerful chief to make head against the Turks. This might be only a pretence for family aggrandisement: but the Emperor became seriously apprehensive lest the Lutherans, if provoked, should abandon the cause of Christendom; and policy therefore conceded what zeal would have refused. By a treaty concluded with the Protestants at Nuremberg, and ratified at Ratisbon in 1531, Charles granted them liberty of conscience, till a council should be held, and annulled all sentences passed against them by the Imperial chamber: on this they engaged to give him powerful assistance against the Turks. In 1535, Muley Hassan, the exiled king of Tunis, implored Charles’s aid against the pirate Barbarossa, who had usurped his throne. The Emperor eagerly seized the opportunity of acquiring fame, by the destruction of that pest of Spain and Italy. He carried a large army into Africa, defeated Barbarossa, and marched to Tunis. The city surrendered, being in no condition to resist: and while the conqueror was deliberating what terms to grant, the soldiery sacked it, committed the most atrocious violence, and are said to have massacred more than thirty thousand persons. This outrage tarnished the glory of the expedition, which was entirely successful. Muley Hassan was restored to his throne.