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 Schönbrunn, while Francis was fleeing to Olmütz and the Archdukes Charles and John were struggling in the defiles of the Alps to disengage themselves from the vanguard of Masséna. The march of the French on Vienna, and thence northwards to Brünn, led to only one incident of general interest, namely, the filching away from the Austrians of the bridge over the Danube to the north of Vienna. As it nears the city, that great river spreads out into several channels, the largest being on the north. The wooden bridge further up the river having been burnt by the Russian rearguard, there remained only the bridge or bridges, opposite the city, on the possession of which Napoleon set much store. He therefore charged Murat and Lannes to secure them if possible.

Murat was smarting under the Emperor's displeasure for a rash advance on Vienna which had wellnigh cost the existence of Mortier's corps on the other bank. Indeed, only by the most resolute bravery did the remnant of that corps hew its way through overwhelming numbers. Murat, who should have kept closely in touch with Mortier by a flotilla of boats, was eager to retrieve his fault, and, with Lannes, Bertrand, and an officer of engineers, he now approached the first part of the bridge as if for a parley during an informal armistice which had just been discussed but not concluded. The French Marshals had disposed the grenadiers of General Oudinot, a body of men as renowned as their leader for fighting qualities, behind some thickets that spread along the southern bank and partly screened the approach. The plank barricade at the southern end was now thrown down, and the four Frenchmen advanced. An Austrian mounted sentinel fired his carbine and galloped away to the main bridge; thereupon the four men advanced, called to the officer there in command as if for a parley, and stopped him in the act of firing the gunpowder stored beneath the bridge, with the assurance that an armistice was, or was about to be, concluded.

Reaching the northern end they repeated their tale, and claimed to see the commander. While the defenders were hesitating, Oudinot's grenadiers were rapidly marching forward. As soon as they were seen, the Austrians prepared once more to fire the bridge. Again they were implored to desist, as peace was as good as signed. But when the grenadiers had reached the northern bank, the mask was dropped: fresh troops were hurrying up and the chance of saving the bridge from their grasp was now lost. By these means did Murat and Lannes secure an undisputed passage to the northern bank, for which four years later the French had desperately to fight. Napoleon was delighted at Murat's exploit, which greatly furthered his pursuit of the allies, and he at once restored that Marshal to high favour. But those who placed gentlemanly conduct above the glamour of a trickster's success were not slow, even then, to express their disapproval of this act of perfidy.[37]

The prolonged retreat into Moravia, the unexpected feebleness of the Hapsburg arms, and the lack of supplies weighed heavily on Alexander's spirits, as is shown in his letter from Olmütz to the King of Prussia on November 19th: "Our position is more than critical: we stand almost alone against the French, who are close on our heels. As for the Austrian army, it does not exist…. If your armies advance, the whole position will alter at once."[38] A few days later, however, when 27,000 more Russians were at hand, including his Imperial Guard, the Czar passed from the depths of depression to the heights of confidence. The caution of his wary commander, Kutusoff, who urged a Fabian policy of delay and retreat, now began to weary him. To retire into northern Hungary seemed ignominious. And though Frederick William held to his resolve of not drawing the sword before December 15th, and by that time the Archduke Charles with a large army was expected below Vienna, yet the susceptible young autocrat spurned the behests of irksome prudence. In vain did Kutusoff and Schwarzenberg urge the need of delay and retreat: Alexander gave more heed to the rash counsels of his younger officers. An advance was ordered on Brünn, and a successful cavalry skirmish at Wischau confirmed the Czar in his change from the strategy of Fabius to that of Varro.

Napoleon, who was now at Brünn, had already divined this change in the temper of his foe, and called back his men with the express purpose of humouring Alexander's latest mood and tempting him on to a decisive battle. He saw clearly the advantage of fighting at once. The renewed offers of an armistice, which he received from the prudent Francis, might alone have convinced him of this; and they came in time to give him an argument, telling enough to daunt the Prussian envoy, who was now drawing near to his headquarters.

After proceeding towards Vienna and being sent back to Brünn, Haugwitz arrived there on November 29th.[39] Of the four hours' private conference that ensued with Napoleon we have but scanty records, and those by Haugwitz himself, who had every reason for warping the truth. He states that he was received with icy coldness, and at once saw that the least threat of hostile pressure by Prussia would drive Napoleon to make a separate peace with Austria. But after the first hour the Emperor appeared