Gustavus Adolphus had witnessed, with great uneasiness, the arts employed by Spain and Austria to detach his allies from him. The more important his alliance with Saxony, the more anxiety the inconstant temper of John George caused him. Between himself and the Elector a sincere friendship could never subsist. A prince, proud of his political importance and accustomed to consider himself as the head of his party, could not see without annoyance the interference of a foreign power in the affairs of the Empire; and nothing but the extreme danger of his dominions could overcome the aversion with which he had long witnessed the progress of this unwelcome intruder. The increasing influence of the king in Germany, his authority with the Protestant states, the unambiguous proofs which he gave of his ambitious views, which were of a character calculated to excite the jealousies of all the states of the Empire, awakened in the Elector's breast a thousand anxieties, which the imperial emissaries did not fail skilfully to keep alive and cherish. Every arbitrary step on the part of the King, every demand, however reasonable, which he addressed to the princes of the Empire, was followed by bitter complaints from the Elector, which seemed to announce an approaching rupture. Even the generals of the two powers, whenever they were called upon to act in common, manifested the same jealousy as divided their leaders. John George's natural aversion to war, and a lingering attachment to Austria, favored the efforts of Arnheim, who, maintaining a constant correspondence with Wallenstein, labored incessantly to effect a private treaty between his master and the Emperor; and if his representatives were long disregarded, still the event proved that they were not altogether without effect.