Irruption of Austria into Bavaria - Breaking-up of the camp of Boulogne - Mission of Duroc to Prussia - The Emperor of Russia visits Berlin - The Duke of Wurtemberg.

ABSORBED by his expedition against England, the Emperor was far from expecting an aggression on the part of any continental power, when he learned by dispatches from Munich that the Austrian army was marching upon that capital.

Austria, no one knew why, unless it was for the purpose of making-war upon us, had collected a considerable army at Wels, under the command of Field-marshal Mack: the pretext for the assemblage of this force was military manoeuvres and exercises, but all at once this army broke up and approached Bavaria.

The Emperor was puzzled to account for this procedure; he had no point in dispute with Austria. That power, it is true, had not recognised the Emperor, but its ambassador had not left Paris.

I am not sure, however, that it had not acknowledged him; for when the Emperor went to Verona, after the coronation at Milan, the Austrian general, Vincent, who commanded the troops of his nation in the Venetian states, came, as I have already related, to pay a personal visit to the Emperor, with all the officers of the troops under his orders ; and the Austrian artillery fired the customary salute. This occurred at the end of June; and, according to all appearance, nobody had the least suspicion of what was to happen in the month of September in the same year. The ambassador of France was at Vienna; the Russian ambassador, indeed, had long before left Paris, but we had yet heard nothing of the march of Russian troops except from the newspapers.

The intelligence, however, was of too serious a nature for the Emperor to neglect it, and he was engaged in too important concerns to give them up lightly. He dispatched his aide-de-camps from Boulogne itself to meet the Austrian army; so difficult was it for him to believe the report of such an incredible aggression. General Bertrand was sent on a similar mission in another direction. I pushed onto the Inn; and, agreeably to my instructions, I reconnoitred a different road for returning from Donauwert to Ludwigsburg and the banks of the Rhine, from the ordinary high-road of Wurtemberg: but before his aide-de-camps had got back, the Emperor received information, not to be doubted, of the departure of Mack's army from Wels, and of the entry of the Austrian territory by the Russians. From this iniquitous aggression date the calamities of France. He hesitated no longer what course to pursue: in fact, he had already lost some time from distrust of the veracity of the intelligence received: he caused, therefore, every thing to be landed. and the army to be re-organised for long marches. It accordingly set out by all the shortest routes for the banks of the Rhine, where it arrived at the same time that the Austrian army reached the Danube. The Elector of Bavaria, with his family and his army, had retired to Wurzburg.

The Emperor, before he left Boulogne, had in haste sent. orders to the banks of the Rhine to collect draught-horses, and to provide as large a quantity as possible of materiel for artillery. We were taken quite unawares; and it required all the activity of the Emperor to supply that army, on the spur of the occasion, with what it needed for the campaign into which it was so suddenly forced.

General Marmont, who was in Holland, had to traverse such countries only, the sovereigns of which have no right to say to a stronger enemy - Why do you pass through my territory? But Bernadotte, who was in Hanover, had part of the Prussian territory to cross; and at the same time that the Emperor sent him orders to march, he dispatched the grand-marshal, Duroc, to Berlin. We were on good terms with Prussia, and in friendly intercourse with its court ; and scarcely two months had elapsed since honorary distinctions had been exchanged between the two countries.

Thus attacked, without declaration of war, the Emperor communicated to the King of Prussia the critical situation in which he was placed by this unexpected aggression: he assured him that he was extremely sorry to be obliged to march his troops over certain portions of the Prussian territory, without any previous negotiation on the subject. He sent his grand-marshal to give him notice of it, and to express his anxious wish that this step might be considered as the result of absolute necessity alone.

Marshal Duroc was received not quite so well as he had been in former missions on which he had been sent to the court of Berlin. The King said little to him concerning the march of Bernadotte: he seemed to be convinced of the validity of the Emperor's motives; and expressed great regret at seeing him forced into a war, which, however, he had no doubt would terminate to his advantage.

Baron Hardenberg was less moderate: on the 14th of October he presented a very warm note to the grand-marshal. " His master," he said, " knew not whether he ought to be more astonished at the violence committed by the French army, or at the motives employed to justify it. Prussia, though she had declared herself neuter, had fulfilled all the obligations which she had contracted : nay, perhaps, she had made sacrifices to France which her duty condemned. And yet, how had the honour and the perseverance which she had shown in her relations of friendship with France been repaid ? The wars of 1796 and 1800 were adduced, when the margraviates had been open to the belligerent parties ; but exception is no rule; and besides, at the periods referred to, every thing had been regulated and stipulated by special conventions. They were left in the dark as to our intentions; but intentions sprang from the very nature of things: the protestations of the royal authorities made them known. Matters of this importance required a positive declaration. But what need has he of a declaration who relies on the inviolability of a generally acknowledged system ? Is it for him to act, when he who meditates the overthrow of what he has sanctioned abstains from doing so? Unknown facts were cited ; wrongs of which they had never been guilty were attributed to the Austrians: what result were such means likely to produce, unless to show in a still stronger light the difference there was between the conduct of the cabinets of Paris and Vienna? The, King, however, would not dwell on the consequences with which they were pregnant: he should merely believe that the Emperor of the French had sufficient motives for annulling the engagements which bound them, and consider, himself thenceforward as released from every kind of obligation. Thus re-established in a position which imposed upon him no other duties than those enjoined by his safety and justice, the King of Prussia would adhere to the principles which he had never ceased to profess, and would neglect nothing to procure for Europe, by his mediation, that peace which he desired for his subjects ; but he declared at the same time that, obstructed every where in his generous intentions, unfettered by engagements, without guarantee for the future, he would provide for the security of his dominions, and set his army in motion."

This declaration was not supported by any direct measure; the grand-marshal continued his stay in Berlin, where he remained nearly a month, during which he witnessed the arrival of the Emperor of Russia, who repaired to that capital Upon pretext of going, before he took the field, to visit his sister, the hereditary Princess of Saxe-Weimar. Nobody could mistake the secret motive of this journey. A person would not quit an army on the eve of important operations, for the purpose of paying a visit more than a hundred leagues distant from the country where it is to act. It was evident that he sought to draw Prussia into the coalition.

I cannot tell what was done and said on this occasion but so much is certain, that while Marshal Duroc was still in Berlin, the Russian army, under the command of General Buxhovden, crossed the Vistula at Warsaw, and marched through Polish Prussia upon Breslau, whence it was to proceed to Bohemia.

The Emperor Napoleon had already calculated and foreseen every thing. The maps of England had disappeared; those of Germany alone were admitted into his cabinet. He made us follow the march of the troops; and one day addressed to us these remarkable words: " If the enemy comes to meet me, I will destroy him before he has repassed the Danube; if he waits for me, I will take him between Augsburg and Ulm." He issued the last orders to the navy and to the army, and set out for Paris. As soon as he had arrived there, he repaired to the senate, explained the motives which had obliged him all at once to change the direction of our forces, and started next day for Strasburg. He reached that city while the army was passing the Rhine, at Kehl, Lauterburg, Spire, and Manheim. He inspected the establishments of the fortress, and pointed out the means of turning to useful purpose a great number of little resources, the application of which he regulated.

He passed the Rhine himself, after giving orders for the reconstruction of the fort of Kehl and seeing the works begun. He had sent proposals to the Prince of Baden and to the Landgrave of Hesse-Darmstadt to ally themselves with him : the two princes delayed answering. The latter thought to elude the question by disbanding his troops, and by making an official communication of the circumstance to the Emperor as a proof of his neutrality; but, after the battle of Austerlitz was won, he was in a great hurry to send protestations of his attachment. The officer who had fulfilled the first mission was charged with the second: two very different parts to act at so short an interval.

The court of Baden acted more frankly; its troops had joined ours before the battle.

While the Emperor was occupied with these matters, the different corps of his army approached the foot of the mountains, situated on the right bank of the river, and entered the country of Wurtemberg. He had sent one of his aide-de-camps to the sovereign of that country, to apprize him that he was obliged to pass through his dominions ; that he was sorry for it, but hoped the passage would take place without disorder.

The Duke of Wurtemberg., shocked at seeing our troops debouch, had collected his little army near Ludwigsburg, his summer residence, and was preparing to make resistance, when the aide-de-camp of the Emperor appeared. This mark of respect pacified him : he, nevertheless, insisted that no troops should pass through his residence. The Emperor arrived a few moments afterwards: the court or Wurtemberg gave him a magnificent reception ; he slept two nights at the palace of Ludwigsburg. It was during his stay there that hostilities commenced on the road from Stuttgard to Ulm, which the corps of Marshal Ney had taken. The Austrians, commanded by the Archduke Ferdinand, under the direction of Field-marshal Mack, had their head-quarters in the latter of those places.

The Emperor manoeuvred on his left, and remained at Ludwigsburg, making Marshal Ney debouch by the high Stuttgard road: the enemy, fully believing that our whole army was following him, manoeuvred accordingly. The Emperor, satisfied with having deceived him, moved with the rapidity of lightning to Nordlingen, where at the same time arrived the corps of Marshal Davout, who had come from Manheim by the valley of the Necker to Bettingen ; that of Marshal Soult, who had come from Spire by Reilbron; and lastly, that of Marshal Lannes, who, leaving Ludwigsburg on his left, had reached Donauwert at the very moment when an Austrian battalion appeared on the right bank of the Danube to destroy the bridge. These troops were driven back to a distance ; and the whole of the cavalry, and afterwards the infantry, were made to cross the river.