While the delays had been going on Altringer, having been joined by the army of the Duke of Feria, quitted the line of the Danube, in spite of Wallenstein's absolute order not to do so, and, evading Horn and Birkenfeldt, marched into Alsace. The Swedish generals, however, pressed hotly upon him, and finally drove him out of Alsace. Ratisbon being left open by Altringer's disobedience to Wallenstein's orders, Duke Bernhard marched upon that city without opposition, and laid siege to it. Maximilian of Bavaria was himself there with a force sufficient to defend the city had he been supported by the inhabitants; but a large majority of the people were Protestants, and, moreover, bitterly hated the Bavarians, who had suppressed their rights as a free city. Maximilian wrote urgently to the emperor and to Wallenstein, pledging himself to maintain Ratisbon if he could receive a reinforcement of 5000 men. The emperor was powerless; he had not the men to send, but he despatched to Wallenstein, one after another, seven messengers, urging him at all hazards to prevent the fall of so important a place. Wallenstein replied to the order that he would do all in his power, and in presence of the messengers ordered the Count of Gallas to march with 12,000 men on Ratisbon, but privately furnished the general with absolute orders, forbidding him on any account to do anything which might bring on an action with the duke. Wallenstein's motives in so acting were, as he afterwards assured the emperor, that he was not strong enough to divide his army, and that he could best cover Vienna by maintaining a strong position in Bohemia, a policy which was afterwards justified by the event. Ratisbon resisted for a short time; but, finding that the promised relief did not arrive, it capitulated on the 5th of November, Maximilian having left the town before the surrender. The duke now pushed on towards Vienna, and captured Straubing and Plattling. John of Werth, who was posted here, not being strong enough to dispute the passage of the Isar, fell back towards the Bohemian frontier, hoping to meet the troops which the emperor had urged Wallenstein to send to his aid, but which never came. Duke Bernhard crossed the Isar unopposed, and on the 12th came within sight of Passau. So far Wallenstein had not moved; he had seemed to comply with the emperor's request to save Ratisbon, but had seemed only, and had not set a man in motion to reinforce John of Werth. He refused, in fact, to fritter away his army. Had he sent Gallas with 12,000 men to join John of Werth, and had their united forces been, as was probable, attacked and defeated by the Swedes, Wallenstein would have been too weak to save the empire. Keeping his army strong he had the key of the position in his hands.