“You can say,” he continues, “that it is to be feared that this increase kindles a fire which may set all Europe in a blaze; that it is the way of youth to be adventurous, and that the alluring visions of heroic fame may disturb and have disturbed the peace of countless nations in the world.” The prospect of acquisitions in the Rhineland seemed first to engage his thoughts. In hopes of winning Berg he not only made overtures to France, but even invited the help of Russia. The fruit of these negotiations was small. Their significance, however, is great, since they showed that Frederick intended to choose his allies without regard to the tradition of his House in favour of Austria, and also that he would not shrink from favouring Muscovite development by employing Cossacks in Western Germany. At the same time that he bargained in this spirit with foreign Powers, Frederick compelled his brother Germans to mark the change of accent which he was introducing into the old language of his House. Brandenburg had taken up the informal protectorate of the German Protestants when the Saxon Elector by becoming Romanist (1697) resigned it. Frederick William devised a safe but effective method of checking Romanist aggression. If any German prince persecuted Protestants, the King of Prussia used forthwith to apply similar oppression to his own papist subjects. Thus, without stirring from Berlin, he stayed the hand of persecutors in the distant valleys of the Neckar and the Salzach. His son soon proved himself ready to go to greater lengths. Claims and counter-claims as to territory had arisen between one of the great Romanist princes, the Archbishop of Mainz, and the Landgrave of Hesse-Cassel, the heir of one of the earliest champions of the Reformation. The former relied on his own troops and on those of neighbouring bishops, while he also possessed the support of the Emperor, whose right to judge the case had been challenged by his opponent. The Landgrave appealed to the King of Prussia and to other princes of the Empire. Frederick’s reply was immediate, emphatic, and successful. “In case of need,” he wrote to his brother-Elector of Mainz, “we should not know how to refrain from affording to the aforementioned His Dilection the Lord Landgrave William the necessary protection and help against unlawful force and disturbance.” At these words the hostile coalition—Elector, bishops, and Emperor—melted away. The young King, it was apparent, had entered the field of German politics with _éclat_.