The illustrious Charles V. had now, for some time, been emperor, and, in the prosecution of his conquests, found it necessary to secure the support of united Germany, especially since Germany was now invaded by the Turks. In order to secure this support, he found it necessary to make concessions in religion to his Protestant subjects. At the diet of Augsburg, (1530,) where there was the most brilliant assemblage of princes which had been for a long time seen in Germany, the celebrated confession of the faith of the Protestants was read. It was written by Melancthon, in both Latin and German, on the basis of the articles of Torgau, which Luther had prepared. The style was Melancthon's; the matter was Luther's. It was comprised in twenty-eight articles, of which twenty-one pertained to the faith of the Protestants--the name they assumed at the second diet of Spires, in 1529--and the remaining seven recounted the errors and abuses of Rome. It was subscribed by the Elector of Saxony, the Marquis of Brandenburg, the Duke of Lunenburg, the Landgrave of Hesse, the Prince of Anhalt, and the deputies of the imperial cities Nuremberg and Reutlingen. But the Catholics had the ascendency in the diet, and the "Confession of Augsburg" was condemned. But the emperor did not venture on any decisive measures for the extirpation of the "heresy." He threatened and published edicts, but his menaces had but little force. Nevertheless, the Protestant princes assembled, first at Smalcalde, and afterwards at Frankfort, for an alliance of mutual defence,--the first effective union of free princes and states against their oppressors in modern Europe,--and laid the foundation of liberty of conscience. Hostilities, however, did not commence, since the emperor was desirous of uniting Germany against the Turks; and he therefore recalled his edicts of Worms and Augsburg against the Protestants, and made important concessions, and promised them undisturbed enjoyment of their religion. This was a great triumph to the Protestants, and as great a shock to the Papal power. [Sidenote: League of Smalcalde.] The Confession of Augsburg and the League of Smalcalde form an important era of Protestantism, since, by these, the reformed faith received its definite form, and was moreover guaranteed. The work for which Luther had been raised up was now, in the main, accomplished. His great message had been delivered and heard. [Sidenote: Death and Character of Luther.]