After long negotiation, Wallenstein, with well-feigned reluctance, consented to relinquish for a few weeks the sweets of private life, and to recruit an army, and bring it under suitable discipline.  He, however, limited the time of his command to three months.  With his boundless wealth and amazing energy, he immediately set all springs in motion.  Adventurers from all parts of Europe, lured by the splendor of his past achievements, crowded his ranks.  In addition to his own vast opulence, the pope and the court of Spain opened freely to him their purses.  As by magic he was in a few weeks at the head of forty thousand men.  In companies, regiments and battalions they were incessantly drilled, and by the close of three months this splendid army, thoroughly furnished, and in the highest state of discipline, was presented to the emperor.  Every step he had taken had convinced, and was intended to convince Ferdinand that his salvation depended upon the energies of Wallenstein.  Gustavus was now, in the full tide of victory, marching from the Rhine to the Danube, threatening to press his conquests even to Vienna.  Ferdinand was compelled to assume the attitude of a suppliant, and to implore his proud general to accept the command of which he had so recently been deprived.  Wallenstein exacted terms so humiliating as in reality to divest the emperor of his imperial power.  He was to be declared generalissimo of all the forces of the empire, and to be invested with unlimited authority.  The emperor pledged himself that neither he nor his son would ever enter the camp.  Wallenstein was to appoint all his officers, distribute all rewards, and the emperor was not allowed to grant either a pardon or a safe-conduct without the confirmation of Wallenstein.  The general was to levy what contribution he pleased upon the vanquished enemy, confiscate property, and no peace or truce was to be made with the enemy without his consent.  Finally, he was to receive, either from the spoils of the enemy, or from the hereditary States of the empire, princely remuneration for his services.

Armed with such enormous power, Wallenstein consented to place himself at the head of the army.  He marched to Prague, and without difficulty took the city.  Gradually he drove the Saxon troops from all their fortresses in Bohemia.  Then advancing to Bavaria, he effected a junction with Bavarian troops, and found himself sufficiently strong to attempt to arrest the march of Gustavus.  The imperial force now amounted to sixty thousand men.  Wallenstein was so sanguine of success, that he boasted that in a few days he would decide the question, whether Gustavus Adolphus or Wallenstein was to be master of the world.  The Swedish king was at Nuremberg with but twenty thousand men, when he heard of the approach of the imperial army, three times outnumbering his own.  Disdaining to retreat, he threw up redoubts, and prepared for a desperate defense.  As Wallenstein brought up his heavy battalions, he was so much overawed by