Meantime the succors which the imperial generals, Goetz and Tiefenbach, were conducting from Silesia, had entered Bohemia, where they were joined by some of Tilly's regiments from the Upper Palatinate. In order to disperse them before they should receive any further reinforcement, Arnheim advanced with part of his army from Prague, and made a vigorous attack on their intrenchments near Limburg, on the Elbe. After a severe action, not without great loss, he drove the enemy from their fortified camp and forced them, by his heavy fire, to recross the Elbe and to destroy the bridge which they had built over that river. Nevertheless, the Imperialists obtained the advantage in several skirmishes, and the Croats pushed their incursions to the very gates of Prague. Brilliant and promising as the opening of the Bohemian campaign had been, the issue by no means satisfied the expectations of Gustavus Adolphus. Instead of vigorously following up their advantages, by forcing a passage to the Swedish army through the conquered country, and then, with it, attacking the imperial power in its centre, the Saxons weakened themselves in a war of skirmishes, in which they were not always successful, while they lost the time which should have been devoted to greater undertakings. But the Elector's subsequent conduct betrayed the motives which had prevented him from pushing his advantage over the Emperor, and by consistent measures promoting the plans of the King of Sweden. The Emperor had now lost the greater part of Bohemia, and the Saxons were advancing against Austria, while the Swedish monarch was rapidly moving to the same point through Franconia, Swabia, and Bavaria. A long war had exhausted the strength of the Austrian monarchy, wasted the country, and diminished its armies. The renown of its victories was no more, as well as the confidence inspired by constant success; its troops had lost the obedience and discipline to which those of the Swedish monarch owed all their superiority in the field. The confederates of the Emperor were disarmed, or their fidelity shaken by the danger which threatened themselves. Even Maximilian of Bavaria, Austria's most powerful ally, seemed disposed to yield to the seductive proposition of neutrality; while his suspicious alliance with France had long been a subject of apprehension to the Emperor. The bishop of Würtzburg and Bamberg, the Elector of Mentz, and the Duke of Lorraine, were either expelled from their territories or threatened with immediate attack; Treves had placed itself under the protection of France. The bravery of the Hollanders gave full employment to the Spanish arms in the Netherlands; while Gustavus had driven them from the Rhine. Poland was still fettered by the truce which subsisted between that country and Sweden. The Hungarian frontier was threatened by the Transylvania Prince, Ragotsky, a successor of Bethlem Gabor and the inheritor of his restless mind;