The hand of France was conspicuous in wresting all these sacrifices from the emperor, and was then still more conspicuous in thwarting his plans for the election of his son. The ambassadors of Richelieu, with diplomatic adroitness, urged upon the diet the Duke of Bavaria as candidate for the imperial crown. This tempting offer silenced the duke, and he could make no more efforts for the emperor. The Protestants greatly preferred the duke to any one of the race of the bigoted Ferdinand. The emperor was excessively chagrined by this aspect of affairs, and abruptly dissolved the diet. He felt that he had been duped by France; that a cunning monk, Richelieu's ambassador, had outwitted him. In his vexation he exclaimed, "A Capuchin friar has disarmed me with his rosary, and covered six electoral caps with his cowl." The emperor was meditating vengeance--the recall of Wallenstein, the reconstruction of the army, the annulling of the edict of toleration, the march of an invading force into the territories of the Duke of Bavaria, and the chastisement of all, Catholics as well as Protestants, who had aided in thwarting his plans--when suddenly a new enemy appeared. Gustavus Adolphus, King of Sweden, reigning over his remote realms on the western shores of the Baltic, though a zealous Protestant, was regarded by Ferdinand as a foe too distant and too feeble to be either respected or feared. But Gustavus, a man of exalted abilities, and of vast energy, was watching with intense interest the despotic strides of the emperor. In his endeavors to mediate in behalf of the Protestants of Germany, he had encountered repeated insults on the part of Ferdinand. The imperial troops were now approaching his own kingdom. They had driven Christian IV., King of Denmark, from his continental territories on the eastern shore of the Baltic, had already taken possession of several of the islands, and were constructing a fleet which threatened the command of that important sea. Gustavus was alarmed, and roused himself to assume the championship of the civil and religious liberties of Europe. He conferred with all the leading Protestant princes, formed alliances, secured funds, stationed troops to protect his own frontiers, and then, assembling the States of his kingdom, entailed the succession of the crown on his only child Christiana, explained to them his plans of war against the emperor, and concluded a dignified and truly pathetic harangue with the following words.