The untiring efforts of Philip of Hesse to unite the two wings of the Protestant forces met with very little success, and the famous conference at Marburg in the autumn of 1529, for which he was responsible, revealed the fact that it was practically impossible for the Lutherans and the Zwinglians to act together even when threatened by a common danger, while a little later the alliance between the Lutheran states of north Germany and the Zwinglian cities of the south was destroyed by differences upon points of doctrine. In 1530 the emperor, flushed with success in Italy and at peace with his foreign foes, came to Germany with the express intention of putting an end to heresy. In June he opened the diet at Augsburg, and here the Lutherans submitted a summary of their doctrines, afterwards called the Augsburg Confession. Drawn up by Melanchthon, this pronouncement was intended to widen the breach between the Lutherans and the Zwinglians, and to narrow that between the Lutherans and the Romanists; from this time it was regarded as the chief standard of the Lutheran faith. Four Zwinglian cities, Strassburg, Constance, Lindau and Memmingen, replied with a confession of their own and the Romanists also drew up an answer. The period of negotiation which followed served only to show that no accommodation was possible. Charles himself made no serious effort to understand the controversy; he was resolved, whether the Lutherans had right on their side or not, that they should submit, and he did not doubt but that he would be able to awe them into submission by an unwonted display of power. But to his surprise the Lutheran princes who attended the diet refused to give way. They were, however, outnumbered by their enemies, and it was the Romanist majority which dictated the terms of the decree, which was laid before the diet in September, enjoining a return to religious conformity within seven months. The Protestant princes could only present a formal protest and leave Augsburg. Finally the decree of the diet, promulgated in November, ordered the execution of the edict of Worms, the restoration of all church property, and the maintenance of the jurisdiction of the bishops. The duty of enforcing the decree was especially entrusted to the _Reichskammergericht_; thus by the processes of law the Protestant princes were to be deprived of much of their property, and it seemed probable that if they did not submit the emperor would have recourse to arms.