In 1530, the Emperor, who had made a separate treaty with the Italian states, received the crown of Lombardy and crown of the Holy Roman Empire from {69} the hands of the Pope at Bologna. On this occasion he was invested with a mantle studded with jewels and some ancient sandals. Ill-health and increasing melancholy clouded his delight in these honours. His aquiline features and dark colouring had formerly given him some claim to beauty, but now the heavy "Hapsburg" jaw began to show the settled obstinacy of a narrow nature. The iron crown of Italy weighed on him heavily, for he was stricken by remorse that he had disregarded the entreaties of the Pope for the rescue of the Knights of St John, whose settlement of Rhodes had been attacked by the Turkish infidels. He gave them Malta in order that he might appease his conscience. Religion claimed much of his attention after the long conflict with France was ended. Heresy was spreading in Germany, where Luther gained a vast number of adherents. Charles issued an edict against the monk, but there was national resistance for him to face as a consequence. In 1530 he renewed the Edict of Worms and was opposed by a League of Protestant princes, who applied for help from England, France, and Denmark against the oppressive Emperor. He would have set himself to crush them if his dominions had not been menaced by Soliman the Magnificent, a Turkish Sultan with an immense army. He was obliged to secure the co-operation of the Protestants against the Turks that he might drive the latter from his eastern frontier. Italians, Flemings, Hungarians, Bohemians, and Burgundians fought side by side with the German troops and drove the invader back to his own territory. When this danger was averted, France suddenly attacked Savoy, and the Emperor found that he must postpone his struggle with the Lutherans. A joint invasion of {70} France by Charles V and Henry VIII of England forced Francis to conclude humiliating peace at Crespy 1544. Three years later the death of the French King left his adversary free to crush the religious liberty of his German subjects. The Emperor, who had declared himself on the side of the Papacy in 1521, now united with the Pope and Charles' brother Ferdinand, who had been given the government of all the Austrian lands. All three were determined to compel Germany to return to the old faith and the old subjection to the Empire. Their resolve seemed to be fulfilled when Maurice, Duke of Saxony, betrayed the Protestant cause, the allies of the German princes proved faithless, and the Elector of Saxony and the Landgrave of Hesse were taken prisoners at Muhlberg in April 1547.