every opportunity of availing himself of his impetuous bravery, take from him the very advantage which had hitherto rendered him invincible.  Without making any attack, therefore, he erected a strong fortified camp on the other side of the Pegnitz, and opposite Nuremberg; and, by this well chosen position, cut off from the city and the camp of Gustavus all supplies from Franconia, Swabia, and Thuringia.  Thus he held in siege at once the city and the King, and flattered himself with the hope of slowly, but surely, wearing out by famine and pestilence the courage of his opponent whom he had no wish to encounter in the field.

Little aware, however, of the resources and the strength of his adversary, Wallenstein had not taken sufficient precautions to avert from himself the fate he was designing for others.  From the whole of the neighboring country, the peasantry had fled with their property; and what little provision remained must be obstinately contested with the Swedes.  The King spared the magazines within the town, as long as it was possible to provision his army from without; and these forays produced constant skirmishes between the Croats and the Swedish cavalry, of which the surrounding country exhibited the most melancholy traces.  The necessaries of life must be obtained sword in hand; and the foraging parties could not venture out without a numerous escort.  And when this supply failed the town opened its magazines to the King, but Wallenstein had to support his troops from a distance.  A large convoy from Bavaria was on its way to him, with an escort of a thousand men.  Gustavus Adolphus having received intelligence of its approach, immediately sent out a regiment of cavalry to intercept it; and the darkness of the night favored the enterprise.  The whole convoy, with the town in which it was, fell into the hands of the Swedes; the Imperial escort was broken up; about 1,200 cattle were carried off; and a thousand wagons, loaded with bread, which could not be brought away, were set on fire.  Seven regiments, which Wallenstein had sent forward to Altdorp to cover the entrance of the long and anxiously expected convoy, were attacked by the King, who had, in like manner, advanced to cover the retreat of his cavalry and routed after an obstinate action, being driven back into the Imperial camp with the loss of 400 men.  So many checks and difficulties, and so firm and unexpected a resistance on the part of the King, made the Duke of Friedland repent that he had declined to hazard a battle.  The strength of the Swedish camp rendered an attack impracticable; and the armed youth of Nuremberg served the King as a nursery from which he could supply his loss of troops.  The want of provisions, which began to be felt in the Imperial camp as strongly as in the Swedish, rendered it uncertain which party would be first compelled to give way.