Gustavus Adolphus, too weak in numbers to cope even with Wallenstein’s force alone, naturally dreaded the junction of such powerful armies, and the little energy he used to prevent it was the occasion of great surprise.  Apparently he reckoned too much on the hatred which alienated the leaders and seemed to render their effectual cooeperation improbable; when the event contradicted his views, it was too late to repair his error.  On the first certain intelligence he received of their designs, he hastened to the Upper Palatinate for the purpose of intercepting the Elector:  but the latter had already arrived there and the junction had been effected at Egra.

This frontier town had been chosen by Wallenstein for the scene of his triumph over his proud rival.  Not content with having seen him, as it were, a suppliant at his feet, he imposed upon him the hard condition of leaving his territories in his rear exposed to the enemy, and declaring by this long march to meet him the necessity and distress to which he was reduced.  Even to this humiliation the haughty prince patiently submitted.  It had cost him a severe struggle to ask for protection of the man who, if his own wishes had been consulted, would never have had the power of granting it:  but having once made up his mind to it, he was ready to bear all the annoyances which were inseparable from that resolve and sufficiently master of himself to put up with petty grievances when an important end was in view.

But whatever pains it had cost to effect this junction, it was equally difficult to settle the conditions on which it was to be maintained.  The united army must be placed under the command of one individual, if any object was to be gained by the union, and each general was equally averse to yield to the superior authority of the other.  If Maximilian rested his claim on his electoral dignity, the nobleness of his descent, and his influence in the empire, Wallenstein’s military renown, and the unlimited command conferred on him by the Emperor, gave an equally strong title to it.  If it was deeply humiliating to the pride of the former to serve under an imperial subject, the idea of imposing laws on so imperious a spirit flattered in the same degree the haughtiness of Wallenstein.  An obstinate dispute ensued, which, however, terminated in a mutual compromise to Wallenstein’s advantage.  To him was assigned the unlimited command of both armies, particularly in battle, while the Elector was deprived of all power of altering the order of battle, or even the route of the army.  He retained only the bare right of punishing and rewarding his own troops and the free use of these when not acting in conjunction with the Imperialists.