Leaving a sufficient force to garrison Glogau, the king ordered all the remaining regiments to be distributed among the other important posts; while Prince Leopold, in high favor, joined the king at Schweidnitz, to assist in the siege of Neisse. Frederick rapidly concentrated his forces for the capture of Neisse before the Austrian army should march for its relief. He thought that the Austrians would not be able to take the field before the snow should disappear and the new spring grass should come, affording forage for their horses. [Illustration: MAP ILLUSTRATING THE MOLLWITZ CAMPAIGN.] But General Neipperg, the Austrian commander-in-chief, proved as watchful, enterprising, and energetic as Frederick. His scouting bands swarmed in all directions. The Prussian foraging parties were cut off, their reconnoitrers were driven back, and all the movements of the main body of the Austrian army were veiled from their view. General Neipperg, hearing of the fall of Glogau, decided, notwithstanding the inclemency of the weather and the snow, to march immediately, with thirty thousand men, to the relief of Neisse. His path led through mountain defiles, over whose steep and icy roads his heavy guns and lumbering ammunition-wagons were with difficulty drawn. At the same time, Frederick, unaware of the movement of the Austrians, prepared to push the siege of Neisse with the utmost vigor. Leaving some of his ablest generals to conduct the operations there, Frederick himself marched, with strong re-enforcements, to strengthen General Schwerin, who was stationed among the Jagerndorf hills, on the southern frontier of Silesia, to prevent the Austrians from getting across the mountains. Marching from Ottmachau, the king met General Schwerin at Neustadt, half way to Jagerndorf, and they returned together to that place. But the swarming horsemen of General Neipperg were so bold and watchful that no information could be obtained of the situation or movements of the Austrian army. Frederick, seeing no indications that General Neipperg was attempting to force his way through the snow-encumbered defiles of the mountains, prepared to return, and, with his concentrated force, press with all vigor the siege of Neisse.