As the Bavarians were too powerful on the Danube, the assembly of the four Upper Circles, which should have been held at Ulm, was removed to Heilbronn, where deputies of more than twelve cities of the empire, with a brilliant crowd of doctors, counts, and princes, attended. The ambassadors of foreign powers likewise, France, England, and Holland, attended this Congress, at which Oxenstiern appeared in person, with all the splendour of the crown whose representative he was. He himself opened the proceedings, and conducted the deliberations. After receiving from all the assembled estates assurances of unshaken fidelity, perseverance, and unity, he required of them solemnly and formally to declare the Emperor and the league as enemies. But desirable as it was for Sweden to exasperate the ill-feeling between the emperor and the estates into a formal rupture, the latter, on the other hand, were equally indisposed to shut out the possibility of reconciliation, by so decided a step, and to place themselves entirely in the hands of the Swedes. They maintained, that any formal declaration of war was useless and superfluous, where the act would speak for itself, and their firmness on this point silenced at last the chancellor. Warmer disputes arose on the third and principal article of the treaty, concerning the means of prosecuting the war, and the quota which the several states ought to furnish for the support of the army. Oxenstiern's maxim, to throw as much as possible of the common burden on the states, did not suit very well with their determination to give as little as possible. The Swedish chancellor now experienced, what had been felt by thirty emperors before him, to their cost, that of all difficult undertakings, the most difficult was to extort money from the Germans. Instead of granting the necessary sums for the new armies to be raised, they eloquently dwelt upon the calamities occasioned by the former, and demanded relief from the old burdens, when they were required to submit to new. The irritation which the chancellor's demand for money raised among the states, gave rise to a thousand complaints; and the outrages committed by the troops, in their marches and quarters, were dwelt upon with a startling minuteness and truth.