The number of the malcontents daily increased; and they even attempted by letters, (which were fortunately intercepted,) to seduce the armies on the Rhine and in Saxony. Neither the representations of Bernard of Weimar, nor the stern reproaches of his harsher associate in command, could suppress this mutiny, while the vehemence of Horn seemed only to increase the insolence of the insurgents. The conditions they insisted on, were that certain towns should be assigned to each regiment for the payment of arrears. Four weeks were allowed to the Swedish Chancellor to comply with these demands; and in case of refusal, they announced that they would pay themselves, and never more draw a sword for Sweden.
These pressing demands, made at the very time when the military chest was exhausted, and credit at a low ebb, greatly embarrassed the chancellor. The remedy, he saw, must be found quickly, before the contagion should spread to the other troops, and he should be deserted by all his armies at once. Among all the Swedish generals, there was only one of sufficient authority and influence with the soldiers to put an end to this dispute. The Duke of Weimar was the favourite of the army, and his prudent moderation had won the good-will of the soldiers, while his military experience had excited their admiration. He now undertook the task of appeasing the discontented troops; but, aware of his importance, he embraced the opportunity to make advantageous stipulations for himself, and to make the embarrassment of the chancellor subservient to his own views.
Gustavus Adolphus had flattered him with the promise of the Duchy of Franconia, to be formed out of the Bishoprics of Wurtzburg and Bamberg, and he now insisted on the performance of this pledge. He at the same time demanded the chief command, as generalissimo of Sweden. The abuse which the Duke of Weimar thus made of his influence, so irritated Oxenstiern, that, in the first moment of his displeasure, he gave him his dismissal from the Swedish service. But he soon thought better of it, and determined, instead of sacrificing so important a leader, to attach him to the Swedish interests at any cost. He therefore granted to him the Franconian bishoprics, as a fief of the Swedish crown, reserving, however, the two fortresses of Wurtzburg and Koenigshofen, which were to be garrisoned by the Swedes; and also engaged, in name of the Swedish crown, to secure these territories to the duke. His demand of the supreme authority was evaded on some specious pretext. The duke did not delay to display his gratitude for this valuable grant, and by his influence and activity soon restored tranquillity to the army. Large sums of money, and still more extensive estates, were divided among the officers, amounting in value to about five millions of dollars, and to which they had no other right but that of conquest. In the mean time, however, the opportunity for a great undertaking had been lost, and the united generals divided their forces to oppose the enemy in other quarters.
Gustavus Horn, after a short inroad into the Upper Palatinate, and the capture of Neumark, directed his march towards the Swabian frontier, where the Imperialists, strongly reinforced, threatened Wuertemberg. At his approach, the enemy retired to the Lake of Constance, but only to show the Swedes the road into a district hitherto unvisited by war. A post on the entrance to Switzerland, would be highly serviceable to the Swedes, and the town of Kostnitz seemed peculiarly well fitted to be a point of communication between him and the confederated cantons. Accordingly, Gustavus Horn immediately commenced the siege of it; but destitute of artillery, for which he was obliged to send to Wirtemberg, he could not press the attack with sufficient vigour, to prevent the enemy from throwing supplies into the town, which the lake afforded them convenient opportunity of doing. He, therefore, after an ineffectual attempt, quitted the place and its neighbourhood, and hastened to meet a more threatening danger upon the Danube.
At the Emperor's instigation, the Cardinal Infante, the brother of Philip IV. of Spain, and the Viceroy of Milan, had raised an army of 14,000 men, intended to act upon the Rhine, independently of Wallenstein, and to protect Alsace. This force now appeared in Bavaria, under the command of the Duke of Feria, a Spaniard; and, that they might be directly employed against the Swedes, Altringer was ordered to join them with his corps. Upon the first intelligence of their approach, Horn had summoned to his assistance the Palsgrave of Birkenfeld, from the Rhine; and being joined by him at Stockach, boldly advanced to meet the enemy's army of 30,000 men.
The latter had taken the route across the Danube into Swabia, where Gustavus Horn came so close upon them, that the two armies were only separated from each other by half a German mile. But, instead of accepting the offer of battle, the Imperialists moved by the Forest towns towards Briesgau and Alsace, where they arrived in time to relieve Breysack, and to arrest the victorious progress of the Rhinegrave, Otto Louis. The latter had, shortly before, taken the Forest towns, and, supported by the Palatine of Birkenfeld, who had liberated the Lower Palatinate and beaten the Duke of Lorraine out of the field, had once more given the superiority to the Swedish arms in that quarter. He was now forced to retire before the superior numbers of the enemy; but Horn and Birkenfeld quickly advanced to his support, and the Imperialists, after a brief triumph, were again expelled from Alsace. The severity of the autumn, in which this hapless retreat had to be conducted, proved fatal to most of the Italians; and their leader, the Duke of Feria, died of grief at the failure of his enterprise.
In the mean time, Duke Bernard of Weimar had taken up his position on the Danube, with eighteen regiments of infantry and 140 squadrons of horse, to cover Franconia, and to watch the movements of the Imperial-Bavarian army upon that river. No sooner had Altringer departed, to join the Italians under Feria, than Bernard, profiting by his absence, hastened across the Danube, and with the rapidity of lightning appeared before Ratisbon. The possession of this town would ensure the success of the Swedish designs upon Bavaria and Austria; it would establish them firmly on the Danube, and provide a safe refuge in case of defeat, while it alone could give permanence to their conquests in that quarter. To defend Ratisbon, was the urgent advice which the dying Tilly left to the Elector; and Gustavus Adolphus had lamented it as an irreparable loss, that the Bavarians had anticipated him in taking possession of this place. Indescribable, therefore, was the consternation of Maximilian, when Duke Bernard suddenly appeared before the town, and prepared in earnest to besiege it.