After the Austrian army under Mack had occupied Ulm, Napoleon, crossing the Danube at Donauwerth, made himself master of Augsburg and Munich. Thus the French army had got in rear of Mack, and cut the communications between the Austrians and Russians, whose leading columns were known to be already at Vienna and coming on by forced marches. The field-marshal then, recognising too late the mistake of allowing himself to be surrounded by the French troops in a circle of which the fortress of Ulm was the centre, tried to get out of it; but was beaten in the successive battles of Werthingen, Gunzburg, and, above all, of Elchingen, where Marshal Ney covered himself with glory, and was closed in more and more until he was compelled to shut himself up in Ulm with his army. The divisions of the Archduke Ferdinand and of Jellachich alone contrived to get away, the former towards Bohemia, the latter towards the Lake of Constance. Ulm was invested by the Emperor, and, although it was not then much fortified, might, nevertheless, owing to its position and its numerous garrison, have held out for a long period and given the Russians time to come to its aid. But Field-Marshal Mack, passing from boastfulness the most overweening to the most utter discouragement, laid down his arms to Napoleon, who had thus in three weeks dispersed, captured, or destroyed 80,000 Austrians, and delivered Bavaria. The Elector was brought back, and we shall see him in 1813 requite the benefit by the most odious treason.

No longer impeded by Mack's army the Emperor hastened his march on Vienna, passing along the right bank of the Danube. He took possession of Passau, then of Linz, where he learnt that 50,000 Russians under General Kutusoff, reinforced by 40,000 Austrians, whom General Kienmayer had succeeded in bringing together, had crossed the Danube at Vienna, and were in position at Mölk and St.-Pölten. At the same time he was informed that the army under the celebrated Archduke Charles had been beaten by Masséna in Venetia, and was retiring by Friuli in the direction of Vienna, and that the Archduke John was occupying Tyrol with several divisions. Thus the two archdukes were threatening the right of the French army, while the Russians were in front of it. To guard against a flank attack, the Emperor, having Augereau's division already in the direction of Bregenz, ordered Ney to invade Tyrol, and sent Marmont's division to Leoben to stop the Archduke Charles on his way from Italy.

Napoleon having thus secured his right flank wished, before advancing to a front attack on the Russians, whose leading division had just come into contact with his, at Amstetten near Steyer, to guard his left flank against any attack from the Austrian troops who had taken refuge in Bohemia, under the Archduke Ferdinand. To this end the Emperor bade Marshal Mortier, with Dupont's and Gazan's divisions of infantry, cross the Danube by the bridges at Passau and Linz, and then descend the river by the left bank, while the main body continued its march on the right bank. Meanwhile, in order not to leave Mortier too much isolated, Napoleon formed the scheme of collecting on the Danube a great number of boats captured on the tributary streams, and forming a flotilla which, under the direction of the marine division of the guard, was to descend the river, keeping always abreast of Mortier's corps, thus uniting the forces on the two banks. You may think it very bold of me to venture on a criticism of one of the great captain's operations, but I cannot refrain from saying that there was no sufficient ground for sending Mortier's division to the left bank, and that it was a mistake which might have had the most awkward results. As a matter of fact the Danube, the greatest river of Europe, is below Passau so broad in winter that one cannot with the naked eye make out a man on the opposite bank. Moreover, it is very deep and swift, and therefore guaranteed perfect security to the left wing of the French army. It would have been enough to break the bridges as we reached them in our march towards Vienna, in order completely to protect the left wing of the army as it marched down the right bank, all the more so that an attack could only come from the Archduke Ferdinand, on the side of Bohemia. But the archduke was only too glad to have escaped from the French before Ulm, and with his small number of troops, and those almost entire cavalry, was not likely to have either the desire or the means of crossing an obstacle like the Danube, in order to attack them at the risk of being hurled back into the river . At the same time, Napoleon, by detaching two of his divisions and isolating them on the further side of this immense river, exposed them to the risk of being captured or cut to pieces, a disaster which was easy to foresee and was very near being realised.

Field-Marshal Kutusoff, who had resolutely awaited the French in the strong position of St.-Pölten, supposing them to be closely pursued by the army of Mack, on becoming aware of the capitulation of that army did not feel himself strong enough to resist Napoleon single handed. Not caring to risk his troops for the defence of the town of Vienna, he decided to put the Danube between himself and the conqueror, and so crossed the river at Krems, burning the bridge behind him. Hardly had he arrived on the left bank with his whole army than he fell in with the scouts of Gazan's division, which was marching from Dürrenstein on Krems, Marshal Mortier at its head. On learning that an isolated French corps existed on the left bank, Kutusoff resolved to crush it. With this view he attacked it in front, on the narrow high road which runs along the Danube, while his light troops, crowning the scarped heights which command the Danube, were to occupy Dürrenstein, and thus cut off Gazan's retreat. The position of the division at that moment was the more critical that the greater part of the flotilla was staying behind, and there were only two small vessels, which offered no facility for bringing reinforcements from the right bank. Thus attacked in front, in rear, and on one flank, by an enemy six tirnes more numerous, shut in moreover between steep rocks occupied by the Russians, and the deep Danube, the French soldiers, crowded as they were on a narrow causeway, were not for one moment demoralised. Marshal Mortier set them a noble example, for the suggestion having been made that he should take advantage of a boat to cross over to the right bank, where he would be safe in the midst of the Grand Army, and thus avoid giving the Russians the glory of capturing a marshal, he replied that he would die with his soldiers or with them pass over the bodies of the Russian. A sanguinary combat with the bayonet ensued, 5,000 French opposed to 30,000 Russians; the horrors of night were added to those of the struggle. Gazan's division in close column managed to regain Dürrenstein at the moment when Dupont's division, which had remained behind opposite Mölk, alarmed by the sound of the cannon, was hastening to its support. The field of battle remained in the possession of the French. In this hand-to-hand fight, where the bayonet was almost exclusively used, our soldiers, being the handier and more active, had an immense advantage over the gigantic Russians. The enemy's loss therefore amounted to 4,500 while ours was 3,000 only. Had our divisions not consisted of veteran troops, Mortier's corps would probably have been destroyed. So well did the Emperor understand this, that he made haste to recall it to the right bank; and what proves to me that he recognised the mistake he had made in throwing this isolated body across the river is that, while he freely rewarded the brave regiments which had fought at Dürrenstein, the bulletins made scarcely any mention of this sanguinary affair. It seemed as if, no explanation satisfactory to military men being possible of this operation beyond the Danube, there was a desire to hush up its consequences. What confirms me still more in the opinion which I make bold to offer is, that in the campaign of 1809 the Emperor, when he found himself on the same ground, did not send any force across the river, but on the contrary kept all his army together during all the march to Vienna.

But to return to my own experiences. When Major Massy and I reached Vienna on the mission entrusted to us by Augereau, Napoleon and the bulk of his army had already left that city, of which they had taken possession without striking a blow. Even the passage of the Danube, which it was necessary to cross in order to pursue the Austrians and Russians, who had retired into Moravia, had not been disputed, thanks to a perhaps not wholly creditable trick employed by Marshals Lannes and Murat. This episode, which had so great an influence on the result of this famous campaign, deserves to be related. The city of Vienna stands on the right bank of the Danube. A small branch of the great river flows through the town, from which the main stream is more than half a league distant. At this point the Danube forms a number of islands, connected by a long series of wooden bridges, the last of which crosses the largest arm, and rests on the left bank at a place called Spitz. Over this long series of bridges runs the road to Moravia. When the Austrians defend the passage across a river, they have the very bad habit of keeping up the bridges till the last moment, in order to retain the power of making counter-attacks. The enemy seldom allows them time to do this, and carries by assault the bridges which they have omitted to burn. The French treated them thus in the campaign of 1796, in the memorable actions of Lodi and Arcola. Even these warnings could not cure the Austrians of the habit. After abandoning Vienna, which was not capable of defence, they retired across the Danube without destroying one of the bridges traversing that mighty stream, and confined themselves to distributing inflammable materials on the flooring of the great bridge, in order to set it on fire when the French appeared. Besides this, they had established on the left bank, at the further end of the bridge of Spitz, a strong battery of artillery and a division of 6,000 men, under the command of Prince Auersperg, a brave soldier, but not a man of much ability. I should mention that a few days before the entry of the French into Vienna, the Emperor had received the Austrian general, Count Gyulai, who came with a flag of truce to make proposals for peace. These had no results; but as soon as the advanced guard had taken possession of Vienna, and Napoleon was established in the royal palace of Schönbrunn, General Gyulai returned and passed more than an hour alone with the Emperor. Thereupon the rumour that an armistice was about to be concluded spread not only among the French regiments as they entered Vienna, but among the Austrian troops who were leaving the town to go across the Danube.

Murat and Lannes, whom the Emperor had ordered to try and make themselves masters of the passage of the river, marched towards the bridge, posted Oudinot's grenadiers in rear of the thick plantations, and then went forward accompanied only by some officers who could speak German. The weak pickets fell back firing on them; the two marshals cried out to the Austrians that there was an armistice, and, continuing to advance, they crossed all the little bridges without hindrance, and having reached the large one, they made the same statement to the officer in command at Spitz. He did not venture to fire upon two marshals, who came almost alone, asserting that hostilities were suspended; but before letting them pass he wished to go himself to General Auersperg and get his orders. While he was gone, leaving the post in charge of a sergeant, Lannes and Murat persuaded the latter that as a condition of the armistice was that the bridge should be given up to them, he with his soldiers must go and rejoin his officer on the left bank. The poor sergeant hesitated; they pushed him gently back, talking to him all the time, and by a slow but uninterrupted movement reached the further end of the great bridge. There an Austrian officer was about to set a light to the inflammable matter; his match was snatched from his hands, and he was told that if he committed such a crime it would be the worse for him. Meantime the column of Oudinot's grenadiers appeared, and got well on to the bridge; the Austrian gunners were about to fire; the French marshals ran towards the commander of artillery and repeated their assurance that an armistice had been concluded; then, sitting down on the guns, they begged the artillerymen to inform General Auersperg of their presence. In course of time he came up, and was on the point of giving the order to fire, although the French grenadiers were by this time surrounding the Austrian batteries and battalions. But the two marshals assured him there was a treaty, and that its first condition was that the French should occupy the bridges. The unhappy general, fearing to get himself into trouble if he shed blood needlessly, lost his head so far as to withdraw, taking with him all the troops which had been given to him to defend the bridges. Without this blunder on the part of General Auersperg, the passage of the Danube would certainly not have been executed without great difficulty; it might even have turned out impracticable; in which case, Napoleon would have been unable to follow the Russian and Austrian armies into Moravia, and his campaign would have failed. He certainly thought so then, and his opinion was confirmed four years later, when, in 1809, the Austrians did burn the bridges over the Danube, and to win the passage of the river we were compelled to fight the two battles of Essling and Wagram at a cost of more than 30,000 men; while in 1805 Marshals Lannes and Murat carried the bridges without having a man wounded. But was the stratagem which they employed permissible? I think not. I know that in time of war people stretch their consciences under the pretext that everything which assures victory may be done, in order to diminish the loss of life, and at the same time gain an advantage to one's country. Still, in spite of these weighty considerations, I do not think that one ought to approve the means employed to get possession of the bridge of Spitz. For my part, I should not like to do the same under similar circumstances.

To conclude this episode I may say that General Auersperg was severely punished for his credulity. A court-martial condemned him to be degraded, to be dragged on a hurdle through the streets of Vienna, and finally to be put to death by the hand of the executioner. The same judgment was pronounced against Field-Marshal Mack for his conduct at Ulm. Both, however, obtained a commutation of the capital sentence to that of imprisonment for life. They were released at the end of ten years, but deprived of their military rank, expelled from the nobility, and repudiated by their families. They both died soon after having regained their freedom.

The stratagem of Lannes and Murat having secured the passage of the Danube, the Emperor marched his army in pursuit of the Austrians and Russians. Herewith begins the second phase of the campaign.