While Gustavus Adolphus was extending his conquests in the south, his generals and allies were gaining similar triumphs in the other provinces. Lower Saxony shook off the yoke of Austria, the enemy abandoned Mecklenburg, and the imperial garrisons retired from the banks of the Weser and the Elbe. In Westphalia and the Upper Rhine, William, Landgrave of Hesse, rendered himself formidable; the Duke of Weimar in Thuringia, and the French in the Electorate of Treves; while to the eastward the whole kingdom of Bohemia was conquered by the Saxons. The Turks were preparing to attack Hungary, and in the heart of Austria a dangerous insurrection was threatened. In vain did the Emperor look around to the courts of Europe for support; in vain did he summon the Spaniards to his assistance, for the bravery of the Flemings afforded them ample employment beyond the Rhine; in vain did he call upon the Roman court and the whole church to come to his rescue. The offended Pope sported, in pompous processions and idle anathemas, with the embarrassments of Ferdinand, and instead of the desired subsidy he was shown the devastation of Mantua.
On all sides of his extensive monarchy hostile arms surrounded him. With the states of the League, now overrun by the enemy, those ramparts were thrown down, behind which Austria had so long defended herself, and the embers of war were now smoldering upon her unguarded frontiers tiers. His most zealous allies were disarmed; Maximilian of Bavaria, his firmest support, was scarce able to defend himself. His armies, weakened by desertion and repeated defeat, and dispirited by continued misfortunes had unlearnt, under beaten generals, that warlike impetuosity which, as it is the consequence, so it is the guarantee of success. The danger was extreme, and extraordinary means alone could raise the imperial power from the degradation into which it was fallen.