On October 10th Hardenberg informed the Austrian ambassador, Metternich, that Frederick William was on the point of declaring for the allies.  Nothing, however, was done until Alexander reached Potsdam, and the first news that he received on his arrival (October 25th) was of the surrender of Ulm.  Nevertheless, the influence of the Czar checkmated the efforts of Haugwitz and the French party, and kept that Government to its resolve, which on November 3rd took the form of the Treaty of Potsdam between Russia, Austria, and Prussia.  Frederick William pledged himself to offer the armed mediation of Prussia, and, if it were refused by Napoleon, to join the allies.  The Prussian demands were as follows:  indemnities for the King of Sardinia in Lombardy, Liguria, and Parma; the independence of Naples, Holland, Germany, and Switzerland; and the Mincio as Austria’s boundary in Italy.[35]

An envoy was to offer these terms to Napoleon, and to bring back a definite answer within one month from the time of his departure, and in the meantime 180,000 Prussians prepared to threaten his flank and rear.  Alexander also secretly pledged himself to use his influence with George III. to gain Hanover for Frederick William at the close of the war, England meanwhile subsidizing Prussia and her Saxon allies on the usual scale.  The Czar afterwards accompanied the King and Queen to the crypt of the Great Frederick, kissed the tomb, and, as he took his leave of their majesties, cast a significant look at the altar.[36]

Did he fear the peace-loving tendencies of the King, or the treachery of Haugwitz?  It is difficult to see good faith in every detail of the treaty.  Apart from the strange assumption that England would subsidize Prussia and also give up Hanover, the manner in which the armed mediation was to be offered left several loopholes for escape.  After the surrender of Ulm, speedy and vigorous action was needed to restore the balance; yet a month’s delay was bargained for.  Then, too, Haugwitz, who was charged with this most important mission, deferred his departure for ten days on the plea that Prussia’s forces could not be ready before the middle of December.  Such was the statement of the leisurely Duke of Brunswick; but it can scarcely be reconciled with Frederick William’s threat, a month earlier, of immediate war against the Russians if they entered his lands.  Yet now that monarch approved of the delay.  Haugwitz therefore did not set out till November 14th, and by that time Napoleon was master of Vienna, and the allies were falling back into Moravia.

We now turn to the scene of war.  For the first time in modern history the Hapsburg capital had fallen into the hands of a foreign foe.  Napoleon now installed himself at the stately palace of Schoenbrunn, while Francis was fleeing to Olmuetz and the Archdukes Charles and John were struggling in the defiles of the Alps to disengage themselves from the vanguard of Massena.  The march of the French on Vienna,