A few preliminary skirmishes resulted in favor of the Austrians, but the first important event was the loss of Schweidnitz, their last hold in Silesia. The garrison, reduced by want and distress, were taken prisoners by Frederick, who then advanced against Olmütz. From thence to Vienna was but a step, and one that was seriously considered by many of the Prussians. But Maria Theresa had again put the right man in the right place—two men, indeed, who proved themselves worthy of her confidence, Daun and Laudon. Daun’s great skill lay in his choice of positions, and he possessed a caution and deliberation that often put Frederick’s patience to the test and defeated his plans. He made no move until he was satisfied as to the fitness of his army, which consisted largely of new troops; but when his preparations were complete he marched to the assistance of Olmütz, which Frederick had besieged. He cut off the supplies of the Prussians by attacking and destroying a heavy train of provisions and ammunition which Frederick was anxiously expecting and depending upon. This loss, together with a sudden attack by Daun, forced the Prussians to raise the siege and retreat. Olmütz was saved. Maria Theresa was greatly relieved, for she realized the importance of Olmütz, and was correspondingly grateful to her commander-in-chief, whose services she had already had good cause to value. She built fresh hopes, too, on the invasion of Brandenburg by the Russians, which obliged Frederick to divide his forces to meet this new danger. Leaving part of his army to oppose Daun, he marched rapidly against the Russians, who were ravaging Prussia. He defeated them with great slaughter at Zorndorf, wreaked a terrible vengeance upon them, and then returned to Saxony, where he was much needed, for his brother Henry was there and was hard pressed by Daun and the Imperial army. Daun employed his usual tactics in making his own position secure, while his light cavalry continually harassed the King’s troops, and in avoiding the decisive action into which Frederick was anxious to force him.