The consequences of Trafalgar lay in the future; the military situation in Germany after Mack's catastrophe was such that nothing could keep the army of Napoleon out of Vienna. In the sudden awakening of Europe to its danger, one solitary gleam of hope appeared in the attitude of the Prussian Court. Napoleon had not scrupled, in his anxiety for the arrival of the Army of Hanover, to order Bernadotte, its commander, to march through the Prussian territory of Anspach, which lay on his direct route towards Ulm. It was subsequently alleged by the Allies that Bernadotte's violation of Prussian neutrality had actually saved him from arriving too late to prevent Mack's escape; but, apart from all imaginary grounds of reproach, the insult offered to Prussia by Napoleon was sufficient to incline even Frederick William to decided action. Some weeks earlier the approach of Russian forces to his frontier had led Frederick William to arm; the French had now more than carried out what the Russians had only suggested. When the outrage was made known to the King of Prussia, that cold and reserved monarch displayed an emotion which those who surrounded him had seldom witnessed. [115] The Czar was forthwith offered a free passage for his armies through Silesia; and, before the news of Mack's capitulation reached the Russian frontier, Alexander himself was on the way to Berlin. The result of the deliberations of the two monarchs was the Treaty of Potsdam, signed on November 3rd. By this treaty Prussia undertook to demand from Napoleon an indemnity for the King of Piedmont, and the evacuation of Germany, Switzerland, and Holland: failing Napoleon's acceptance of Prussia's mediation upon these terms, Prussia engaged to take the field with 180,000 men. [French enter Vienna, Nov. 13.]