The Imperialists, under Leopold and Piccolomini, immediately hastened by Dresden to its relief, and Torstensohn, to avoid being inclosed between this army and the town, boldly advanced to meet them in order of battle. By a strange coincidence, the two armies met upon the very spot which, eleven years before, Gustavus Adolphus had rendered remarkable by a decisive victory; and the heroism of their predecessors, now kindled in the Swedes a noble emulation on this consecrated ground. The Swedish generals, Stahlhantsch and Wellenberg, led their divisions with such impetuosity upon the left wing of the Imperialists, before it was completely formed, that the whole cavalry that covered it were dispersed and rendered unserviceable. But the left of the Swedes was threatened with a similar fate, when the victorious right advanced to its assistance, took the enemy in flank and rear, and divided the Austrian line. The infantry on both sides stood firm as a wall, and when their ammunition was exhausted, maintained the combat with the butt-ends of their muskets, till at last the Imperialists, completely surrounded, after a contest of three hours, were compelled to abandon the field. The generals on both sides had more than once to rally their flying troops; and the Archduke Leopold, with his regiment, was the first in the attack and last in flight. But this bloody victory cost the Swedes more than 3000 men, and two of their best generals, Schlangen and Lilienhoeck. More than 5000 of the Imperialists were left upon the field, and nearly as many taken prisoners. Their whole artillery, consisting of 46 field-pieces, the silver plate and portfolio of the archduke, with the whole baggage of the army, fell into the hands of the victors. Torstensohn, too greatly disabled by his victory to pursue the enemy, moved upon Leipzig. The defeated army retired into Bohemia, where its shattered regiments reassembled. The Archduke Leopold could not recover from the vexation caused by this defeat; and the regiment of cavalry which, by its premature flight, had occasioned the disaster, experienced the effects of his indignation. At Raconitz in Bohemia, in presence of the whole army, he publicly declared it infamous, deprived it of its horses, arms, and ensigns, ordered its standards to be torn, condemned to death several of the officers, and decimated the privates.
The surrender of Leipzig, three weeks after the battle, was its brilliant result. The city was obliged to clothe the Swedish troops anew, and to purchase an exemption from plunder, by a contribution of 300,000 rix-dollars, to which all the foreign merchants, who had warehouses in the city, were to furnish their quota. In the middle of winter, Torstensohn advanced against Freyberg, and for several weeks defied the inclemency of the season, hoping by his perseverance to weary out the obstinacy of the besieged. But he found that he was merely sacrificing the lives of his soldiers; and at last, the approach of the imperial general, Piccolomini, compelled him, with his weakened army, to retire. He considered it, however, as equivalent to a victory, to have disturbed the repose of the enemy in their winter quarters, who, by the severity of the weather, sustained a loss of 3000 horses. He now made a movement towards the Oder, as if with the view of reinforcing himself with the garrisons of Pomerania and Silesia; but, with the rapidity of lightning, he again appeared upon the Bohemian frontier, penetrated through that kingdom, and relieved Olmutz in Moravia, which was hard pressed by the Imperialists. His camp at Dobitschau, two miles from Olmutz, commanded the whole of Moravia, on which he levied heavy contributions, and carried his ravages almost to the gates of Vienna. In vain did the Emperor attempt to arm the Hungarian nobility in defence of this province; they appealed to their privileges, and refused to serve beyond the limits of their own country. Thus, the time that should have been spent in active resistance, was lost in fruitless negociation, and the entire province was abandoned to the ravages of the Swedes.
While Torstensohn, by his marches and his victories, astonished friend and foe, the armies of the allies had not been inactive in other parts of the empire. The troops of Hesse, under Count Eberstein, and those of Weimar, under Mareschal de Guebriant, had fallen into the Electorate of Cologne, in order to take up their winter quarters there. To get rid of these troublesome guests, the Elector called to his assistance the imperial general Hatzfeldt, and assembled his own troops under General Lamboy. The latter was attacked by the allies in January, 1642, and in a decisive action near Kempen, defeated, with the loss of about 2000 men killed, and about twice as many prisoners. This important victory opened to them the whole Electorate and neighbouring territories, so that the allies were not only enabled to maintain their winter quarters there, but drew from the country large supplies of men and horses.
Guebriant left the Hessians to defend their conquests on the Lower Rhine against Hatzfeldt, and advanced towards Thuringia, as if to second the operations of Torstensohn in Saxony. But instead of joining the Swedes, he soon hurried back to the Rhine and the Maine, from which he seemed to think he had removed farther than was expedient. But being anticipated in the Margraviate of Baden, by the Bavarians under Mercy and John de Werth, he was obliged to wander about for several weeks, exposed, without shelter, to the inclemency of the winter, and generally encamping upon the snow, till he found a miserable refuge in Breisgau. He at last took the field; and, in the next summer, by keeping the Bavarian army employed in Suabia, prevented it from relieving Thionville, which was besieged by Conde. But the superiority of the enemy soon drove him back to Alsace, where he awaited a reinforcement.
The death of Cardinal Richelieu took place in November, 1642, and the subsequent change in the throne and in the ministry, occasioned by the death of Louis XIII., had for some time withdrawn the attention of France from the German war, and was the cause of the inaction of its troops in the field. But Mazarin, the inheritor, not only of Richelieu's power, but also of his principles and his projects, followed out with renewed zeal the plans of his predecessor, though the French subject was destined to pay dearly enough for the political greatness of his country. The main strength of its armies, which Richelieu had employed against the Spaniards, was by Mazarin directed against the Emperor; and the anxiety with which he carried on the war in Germany, proved the sincerity of his opinion, that the German army was the right arm of his king, and a wall of safety around France. Immediately upon the surrender of Thionville, he sent a considerable reinforcement to Field-Marshal Guebriant in Alsace; and to encourage the troops to bear the fatigues of the German war, the celebrated victor of Rocroi, the Duke of Enghien, afterwards Prince of Conde, was placed at their head. Guebriant now felt himself strong enough to appear again in Germany with repute. He hastened across the Rhine with the view of procuring better winter quarters in Suabia, and actually made himself master of Rothweil, where a Bavarian magazine fell into his hands. But the place was too dearly purchased for its worth, and was again lost even more speedily than it had been taken. Guebriant received a wound in the arm, which the surgeon's unskilfulness rendered mortal, and the extent of his loss was felt on the very day of his death.