Torstensohn rapidly followed up his victory; and while Axel Lilienstern, one of the generals who commanded under him, overawed Saxony, and Koenigsmark subdued the whole of Bremen, he himself penetrated into Bohemia with 16,000 men and 80 pieces of artillery, and endeavoured a second time to remove the seat of war into the hereditary dominions of Austria. Ferdinand, upon this intelligence, hastened in person to Prague, in order to animate the courage of the people by his presence; and as a skilful general was much required, and so little unanimity prevailed among the numerous leaders, he hoped in the immediate neighbourhood of the war to be able to give more energy and activity. In obedience to his orders, Hatzfeldt assembled the whole Austrian and Bavarian force, and contrary to his own inclination and advice, formed the Emperor's last army, and the last bulwark of his states, in order of battle, to meet the enemy, who were approaching, at Jankowitz, on the 24th of February, 1645. Ferdinand depended upon his cavalry, which outnumbered that of the enemy by 3000, and upon the promise of the Virgin Mary, who had appeared to him in a dream, and given him the strongest assurances of a complete victory.
The superiority of the Imperialists did not intimidate Torstensohn, who was not accustomed to number his antagonists. On the very first onset, the left wing, which Goetz, the general of the League, had entangled in a disadvantageous position among marshes and thickets, was totally routed; the general, with the greater part of his men, killed, and almost the whole ammunition of the army taken. This unfortunate commencement decided the fate of the day. The Swedes, constantly advancing, successively carried all the most commanding heights. After a bloody engagement of eight hours, a desperate attack on the part of the Imperial cavalry, and a vigorous resistance by the Swedish infantry, the latter remained in possession of the field. 2,000 Austrians were killed upon the spot, and Hatzfeldt himself, with 3,000 men, taken prisoners. Thus, on the same day, did the Emperor lose his best general and his last army.
This decisive victory at Jancowitz, at once exposed all the Austrian territory to the enemy. Ferdinand hastily fled to Vienna, to provide for its defence, and to save his family and his treasures. In a very short time, the victorious Swedes poured, like an inundation, upon Moravia and Austria. After they had subdued nearly the whole of Moravia, invested Brunn, and taken all the strongholds as far as the Danube, and carried the intrenchments at the Wolf's Bridge, near Vienna, they at last appeared in sight of that capital, while the care which they had taken to fortify their conquests, showed that their visit was not likely to be a short one. After a long and destructive circuit through every province of Germany, the stream of war had at last rolled backwards to its source, and the roar of the Swedish artillery now reminded the terrified inhabitants of those balls which, twenty-seven years before, the Bohemian rebels had fired into Vienna. The same theatre of war brought again similar actors on the scene. Torstensohn invited Ragotsky, the successor of Bethlen Gabor, to his assistance, as the Bohemian rebels had solicited that of his predecessor; Upper Hungary was already inundated by his troops, and his union with the Swedes was daily apprehended. The Elector of Saxony, driven to despair by the Swedes taking up their quarters within his territories, and abandoned by the Emperor, who, after the defeat at Jankowitz, was unable to defend himself, at length adopted the last and only expedient which remained, and concluded a truce with Sweden, which was renewed from year to year, till the general peace. The Emperor thus lost a friend, while a new enemy was appearing at his very gates, his armies dispersed, and his allies in other quarters of Germany defeated. The French army had effaced the disgrace of their defeat at Deutlingen by a brilliant campaign, and had kept the whole force of Bavaria employed upon the Rhine and in Suabia. Reinforced with fresh troops from France, which the great Turenne, already distinguished by his victories in Italy, brought to the assistance of the Duke of Enghien, they appeared on the 3rd of August, 1644, before Friburg, which Mercy had lately taken, and now covered, with his whole army strongly intrenched. But against the steady firmness of the Bavarians, all the impetuous valour of the French was exerted in vain, and after a fruitless sacrifice of 6,000 men, the Duke of Enghien was compelled to retreat. Mazarin shed tears over this great loss, which Conde, who had no feeling for anything but glory, disregarded. "A single night in Paris," said he, "gives birth to more men than this action has destroyed." The Bavarians, however, were so disabled by this murderous battle, that, far from being in a condition to relieve Austria from the menaced dangers, they were too weak even to defend the banks of the Rhine. Spires, Worms, and Manheim capitulated; the strong fortress of Philipsburg was forced to surrender by famine; and, by a timely submission, Mentz hastened to disarm the conquerors.
Austria and Moravia, however, were now freed from Torstensohn, by a similar means of deliverance, as in the beginning of the war had saved them from the Bohemians. Ragotzky, at the head of 25,000 men, had advanced into the neighbourhood of the Swedish quarters upon the Danube. But these wild undisciplined hordes, instead of seconding the operations of Torstensohn by any vigorous enterprise, only ravaged the country, and increased the distress which, even before their arrival, had begun to be felt in the Swedish camp. To extort tribute from the Emperor, and money and plunder from his subjects, was the sole object that had allured Ragotzky, or his predecessor, Bethlen Gabor, into the field; and both departed as soon as they had gained their end. To get rid of him, Ferdinand granted the barbarian whatever he asked, and, by a small sacrifice, freed his states of this formidable enemy.
In the mean time, the main body of the Swedes had been greatly weakened by a tedious encampment before Brunn. Torstensohn, who commanded in person, for four entire months employed in vain all his knowledge of military tactics; the obstinacy of the resistance was equal to that of the assault; while despair roused the courage of Souches, the commandant, a Swedish deserter, who had no hope of pardon. The ravages caused by pestilence, arising from famine, want of cleanliness, and the use of unripe fruit, during their tedious and unhealthy encampment, with the sudden retreat of the Prince of Transylvania, at last compelled the Swedish leader to raise the siege. As all the passes upon the Danube were occupied, and his army greatly weakened by famine and sickness, he at last relinquished his intended plan of operations against Austria and Moravia, and contented himself with securing a key to these provinces, by leaving behind him Swedish garrisons in the conquered fortresses. He then directed his march into Bohemia, whither he was followed by the Imperialists, under the Archduke Leopold. Such of the lost places as had not been retaken by the latter, were recovered, after his departure, by the Austrian General Bucheim; so that, in the course of the following year, the Austrian frontier was again cleared of the enemy, and Vienna escaped with mere alarm. In Bohemia and Silesia too, the Swedes maintained themselves only with a very variable fortune; they traversed both countries, without being able to hold their ground in either. But if the designs of Torstensohn were not crowned with all the success which they were promised at the commencement, they were, nevertheless, productive of the most important consequences to the Swedish party. Denmark had been compelled to a peace, Saxony to a truce. The Emperor, in the deliberations for a peace, offered greater concessions; France became more manageable; and Sweden itself bolder and more confident in its bearing towards these two crowns. Having thus nobly performed his duty, the author of these advantages retired, adorned with laurels, into the tranquillity of private life, and endeavoured to restore his shattered health.