The King of Poland’s enmity was not seconded by his ability. He endeavoured in vain to shake the fidelity of Gustavus’s subjects, and he tried the fortune of war with no better success. In the contests between the cousins, which occurred in the first ten years of Gustavus’s reign, the advantage was always on the side of Sweden. Gustavus was desirous of peace, and forbore to press his superiority. But Sigismond’s hostility was nourished and stimulated by the leading Catholic powers, Spain and Austria; and he made so bad a return for this moderation, that in 1621 the war was renewed in a more determined manner, and in the course of eight years Livonia, Courland, and Polish Prussia, were gradually subjected to Sweden. During this time Gustavus was no careless spectator of the Thirty Years’ War, which was raging in Germany. However well inclined he might be to step forward as the defender of the Protestant cause, he could not do so with effect while his exertions were demanded in Poland; and though he made an offer of assistance to the Protestants in 1626, it was clogged with conditions which induced them to decline his proposals. But in 1629, under the mediation of France, he concluded a truce for six years with Sigismond, retaining possession of the conquered provinces; and being thus relieved from all fear of Poland, and guaranteed against injury from Denmark by the interest of that country in checking the progress of the Imperial arms, he found himself qualified to take the decisive part which he had long desired in the affairs of Germany. How far his determination was influenced by personal and ambitious motives, how far it was due to patriotism and religious zeal, it must be left to each inquirer to decide for himself. The crisis was one of extreme importance: for the temporal rights of the whole German empire were endangered by the inordinate and seemingly prosperous ambition of the House of Austria; and the Protestant states in particular had reason to apprehend the speedy destruction of their own, and the re-establishment of the Roman Catholic church. And if the influence of the Emperor, Ferdinand II., supported by the papal hierarchy re-established in its great power and rich benefices through the north of Germany, were suffered unchecked to extend itself to the Baltic sea, the liberties of Sweden and Denmark, and the very existence of the Reformation on the Continent, seemed to be involved in no remote danger. To pull down the power of Ferdinand and the Catholic League thus became of vital moment to the King of Sweden. But though the Protestant princes were ready to invoke his assistance in secret complaints, none of them dared to conclude an open treaty with a distant prince, and a kingdom hitherto obscure, and thus to incur the resentment of the Emperor, whose formidable armies, anxious above all things for the renewal of war and rapine, were at hand. Moreover, the jealousy and