These concessions on the part of the States, demanded some return from Sweden. A few weeks after the death of Gustavus Adolphus, sorrow ended the days of the unfortunate Elector Palatine. For eight months he had swelled the pomp of his protector's court, and expended on it the small remainder of his patrimony. He was, at last, approaching the goal of his wishes, and the prospect of a brighter future was opening, when death deprived him of his protector. But what he regarded as the greatest calamity, was highly favourable to his heirs. Gustavus might venture to delay the restoration of his dominions, or to load the gift with hard conditions; but Oxenstiern, to whom the friendship of England, Holland, and Brandenburg, and the good opinion of the Reformed States were indispensable, felt the necessity of immediately fulfilling the obligations of justice. At this assembly, at Heilbronn, therefore, he engaged to surrender to Frederick's heirs the whole Palatinate, both the part already conquered, and that which remained to be conquered, with the exception of Manheim, which the Swedes were to hold, until they should be indemnified for their expenses. The Chancellor did not confine his liberality to the family of the Palatine alone; the other allied princes received proofs, though at a later period, of the gratitude of Sweden, which, however, she dispensed at little cost to herself.
Impartiality, the most sacred obligation of the historian, here compels us to an admission, not much to the honour of the champions of German liberty. However the Protestant Princes might boast of the justice of their cause, and the sincerity of their conviction, still the motives from which they acted were selfish enough; and the desire of stripping others of their possessions, had at least as great a share in the commencement of hostilities, as the fear of being deprived of their own. Gustavus soon found that he might reckon much more on these selfish motives, than on their patriotic zeal, and did not fail to avail himself of them. Each of his confederates received from him the promise of some possession, either already wrested, or to be afterwards taken from the enemy; and death alone prevented him from fulfilling these engagements. What prudence had suggested to the king, necessity now prescribed to his successor. If it was his object to continue the war, he must be ready to divide the spoil among the allies, and promise them advantages from the confusion which it was his object to continue. Thus he promised to the Landgrave of Hesse, the abbacies of Paderborn, Corvey, Munster, and Fulda; to Duke Bernard of Weimar, the Franconian Bishoprics; to the Duke of Wirtemberg, the Ecclesiastical domains, and the Austrian counties lying within his territories, all under the title of fiefs of Sweden. This spectacle, so strange and so dishonourable to the German character, surprised the Chancellor, who found it difficult to repress his contempt, and on one occasion exclaimed, "Let it be writ in our records, for an everlasting memorial, that a German prince made such a request of a Swedish nobleman, and that the Swedish nobleman granted it to the German upon German ground!"
After these successful measures, he was in a condition to take the field, and prosecute the war with fresh vigour. Soon after the victory at Lutzen, the troops of Saxony and Lunenburg united with the Swedish main body; and the Imperialists were, in a short time, totally driven from Saxony. The united army again divided: the Saxons marched towards Lusatia and Silesia, to act in conjunction with Count Thurn against the Austrians in that quarter; a part of the Swedish army was led by the Duke of Weimar into Franconia, and the other by George, Duke of Brunswick, into Westphalia and Lower Saxony.
The conquests on the Lech and the Danube, during Gustavus's expedition into Saxony, had been maintained by the Palatine of Birkenfeld, and the Swedish General Banner, against the Bavarians; but unable to hold their ground against the victorious progress of the latter, supported as they were by the bravery and military experience of the Imperial General Altringer, they were under the necessity of summoning the Swedish General Horn to their assistance, from Alsace. This experienced general having captured the towns of Benfeld, Schlettstadt, Colmar, and Hagenau, committed the defence of them to the Rhinegrave Otto Louis, and hastily crossed the Rhine to form a junction with Banner's army. But although the combined force amounted to more than 16,000, they could not prevent the enemy from obtaining a strong position on the Swabian frontier, taking Kempten, and being joined by seven regiments from Bohemia. In order to retain the command of the important banks of the Lech and the Danube, they were under the necessity of recalling the Rhinegrave Otto Louis from Alsace, where he had, after the departure of Horn, found it difficult to defend himself against the exasperated peasantry. With his army, he was now summoned to strengthen the army on the Danube; and as even this reinforcement was insufficient, Duke Bernard of Weimar was earnestly pressed to turn his arms into this quarter.
Duke Bernard, soon after the opening of the campaign of 1633, had made himself master of the town and territory of Bamberg, and was now threatening Wurtzburg. But on receiving the summons of General Horn, without delay he began his march towards the Danube, defeated on his way a Bavarian army under John de Werth, and joined the Swedes near Donauwerth. This numerous force, commanded by excellent generals, now threatened Bavaria with a fearful inroad. The bishopric of Eichstadt was completely overrun, and Ingoldstadt was on the point of being delivered up by treachery to the Swedes. Altringer, fettered in his movements by the express order of the Duke of Friedland, and left without assistance from Bohemia, was unable to check the progress of the enemy. The most favourable circumstances combined to further the progress of the Swedish arms in this quarter, when the operations of the army were at once stopped by a mutiny among the officers.
All the previous successes in Germany were owing altogether to arms; the greatness of Gustavus himself was the work of the army, the fruit of their discipline, their bravery, and their persevering courage under numberless dangers and privations. However wisely his plans were laid in the cabinet, it was to the army ultimately that he was indebted for their execution; and the expanding designs of the general did but continually impose new burdens on the soldiers. All the decisive advantages of the war, had been violently gained by a barbarous sacrifice of the soldiers' lives in winter campaigns, forced marches, stormings, and pitched battles; for it was Gustavus's maxim never to decline a battle, so long as it cost him nothing but men. The soldiers could not long be kept ignorant of their own importance, and they justly demanded a share in the spoil which had been won by their own blood. Yet, frequently, they hardly received their pay; and the rapacity of individual generals, or the wants of the state, generally swallowed up the greater part of the sums raised by contributions, or levied upon the conquered provinces. For all the privations he endured, the soldier had no other recompense than the doubtful chance either of plunder or promotion, in both of which he was often disappointed. During the lifetime of Gustavus Adolphus, the combined influence of fear and hope had suppressed any open complaint, but after his death, the murmurs were loud and universal; and the soldiery seized the most dangerous moment to impress their superiors with a sense of their importance. Two officers, Pfuhl and Mitschefal, notorious as restless characters, even during the King's life, set the example in the camp on the Danube, which in a few days was imitated by almost all the officers of the army. They solemnly bound themselves to obey no orders, till these arrears, now outstanding for months, and even years, should be paid up, and a gratuity, either in money or lands, made to each man, according to his services. "Immense sums," they said, "were daily raised by contributions, and all dissipated by a few. They were called out to serve amidst frost and snow, and no reward requited their incessant labours. The soldiers' excesses at Heilbronn had been blamed, but no one ever talked of their services. The world rung with the tidings of conquests and victories, but it was by their hands that they had been fought and won."