As soon as Gustavus got away from the vitiated air around Nuremberg out into the good atmosphere of the country on horseback he regained all lost enthusiasm, and was ready for the initiative, and he decided that only a division under Bernard should go to the assistance of John George of Saxony, and he would again try for the hereditary lands of both the emperor and Wallenstein. That would keep the Elector Maximilian with his little army of ten thousand from being with Wallenstein. Oxenstiern, who seems to have left Nuremberg soon after the enemy had broken camp and moved northward, strongly advised a division, one reason being subsistence. The king then left Bernard with eight thousand men in Franconia, with orders to move northward in a line nearly parallel with Wallenstein. One division of ten thousand he sent to garrisons, and with not more then ten thousand of his choice men he again crossed the Danube and Lech for the purpose of attacking Ingolstadt. Maximilian made a great cry to Wallenstein to come to his assistance, but the general laughed at him, saying, "Protect yourself."
Wallenstein was making for Saxony because it was the richest portion of the country, and he really hoped Maximilian would be humiliated by a defeat.
General Arnin commanded the army of Saxony, which numbered about twenty thousand men. Much of the fluctuating conduct of the Elector must be placed to the discredit of this Catholic adviser whose heart was always with the emperor and not with his king and country.
Oxenstiern came up on the west bank of the river, and in Alsace had possessed himself of Strasburg, then a free imperial city. He also drove the Spaniards and Lorainers before him, and they were this time, for the most part, driven from German soil. Pappenheim and Tott were keeping each other occupied on the Weser, so that neither could help the main army to which he belonged, but the Swedes had the Archbishopric of Bremen, and Gustavus felt that it was necessary to win one great battle on account of all that floating element which shouts only with the winner. They must be again brought to shout for the Protestant side.
Wallenstein attacked Schweinfurt after losing Maximilian's division. Bernard rushed to the defence of the city, and Wallenstein, having double the number of soldiers, retired.
Then Bernard protected the passes through the Thuringian forests, and kept the way open for Gustavus and the main body of the Protestant army to make its way to Erfurth.
Pappenheim was almost if not altogether as ruthless as Wallenstein, but morally a better man. The latter kept ordering the former to join him, but Pappenheim had so long been in independent command that he hated to do this. For one thing, the stealings would have to be reported, and, for another, General Tott would harass the rear of his army, but at length a junction of the two armies was made a few days before Gustavus entered Saxony, which was October 21st.
Wallenstein, as a sort of warning of the coming scourge, sent Colonel Hölch with the most savage of the Croats into Saxony, and while he wrote hypocritical letters to the effect that the peasantry should not be molested, yet the robbers knew they were to leave nothing behind them.
Gustavus was again all ready for his attack on Ingolstadt October 8th, when a courier from Oxenstiern informed him that not only Hölch's regiment, but Wallenstein's main army, twenty thousand strong, had crossed into Saxony on October 5th. He decided at once to call in all divisions of his army and to concentrate at Erfurth. On the 12th he was joined by Oxenstiern and Knipenhausen. As they marched through those great forests he kept his friend and chancellor much by his side. He talked over with Oxenstiern what should be the terms of peace, when it could be made, and distinctly told him that in the case of the death of his king he, as chancellor, must bring the war sooner or later to a successful close. Also he talked of the government at home, of his wife, but most of all of the little maid upon whom the sorrow of ruling an impoverished kingdom would fall, should he lose his life.
On October 28th the army was at Erfurth, having marched from Bavaria in eighteen days. Wallenstein declared, "To do that they must have flown."