But Mack forgot two essential facts. Until the Russians arrived, he was too weak to hold so advanced a position in what was hostile ground, now that Bavaria and the other South German States obeyed Napoleon's summons to range themselves on his side. Further, he was dangerously exposed on the north, as a glance at the map will show. Ulm and the line of the Iller formed a strong defence against the south-west: but on the north that position is singularly open: it can be turned from the valleys of the Main, the Neckar, and the Altmühl, all of which conduct an invader to the regions east of Ulm. Indeed, it passes belief how even the Aulic Council could have ignored the dangers of that position. Possibly the fact that Ulm had been stoutly held by Kray in 1796 now induced them to overrate its present importance; but at that time the fortified camp of Ulm was the central knot of vast operations, whereas now it was but an advanced outpost.[24] If Francis and his advisers were swayed by historical reminiscences it is strange that they forgot the fate of Melas in Piedmont. The real parallel had been provided, not by Kray, but by the general who was cut off at Marengo. Indeed, in its broad outlines, the campaign of Ulm resembles that of Marengo. Against foes who had thrust their columns far from their base, Napoleon now, as in 1800, determined to deal a crushing blow. On the part of the Austrians we notice the same misplaced confidence, the same lack of timely news, and the same inability to understand Napoleon's plan until his dispositions are complete; while his strategy and tactics in 1805 recall to one's mind the masterly simplicity of design, the subtlety and energy of execution, which led up to his triumph in the plains of Piedmont.
Meanwhile the allies were dissipating their strength. A Russian corps, acting from Corfu as a base, and an English expedition from Malta, were jointly to attack St. Cyr in the south of Italy, raise the country at his rear and compel him to surrender. This plan was left helplessly flapping in the air by a convention which Napoleon imposed on the Neapolitan ambassador. On September 21st Talleyrand induced that envoy to guarantee the neutrality of the kingdom of Naples, all belligerents being excluded from its domains. Consequently St. Cyr's corps evacuated that land and brought a welcome reinforcement to Masséna on the Mincio. Equally skilful was Napoleon's action as regards Hanover. On that side also the allies planned a formidable expedition. From the fortress of Stralsund in Swedish Pomerania, a force of Russians and Swedes, which Gustavus burned to command, was to march into Hanover, and, when strengthened by an Anglo-Hanoverian corps, drive the French from the Low Countries. It is curious to contrast the cumbrous negotiations concerning this expedition—the quarrels about the command, the anxiety at the outset lest Villeneuve should perhaps sail into the Baltic, the delays of the British War Office, the remonstrances of the Czar, and the efforts to avert the jealousy of Prussia—with the serene indifference of Napoleon as to the whole affair. He knew full well that the war would not be decided by diversions at the heel of Italy or on the banks of the Ems, but by the shock of great masses of men on the Danube. He denuded Hanover of French troops, except at its southern fortress of Hameln, so that he could overwhelm the levies of Austria before the Russians came up. In brief, while the Coalition sought, like a Briareus, to envelop him on all sides, he prepared to deal a blow at its heart.
As the first part of the campaign depended almost entirely on problems of time and space, it will be well to follow the chief movements of the hostile forces somewhat closely. The Austrian plan aimed at forestalling the French in the occupation of Swabia; and its apparent success puffed up Mack with boundless confidence. At Ulm he threw up extensive outworks to strengthen that obsolete fortress, extended his lines to Memmingen far on the south, and trusted that the Muscovites would come up long before the French eagles hovered above the sources of the Danube. But at that time the Russian vanguard had not reached Linz in Upper Austria, and not before October 10th did it appear on the banks of the River Inn.[25]
Far from being the last to move, the French Emperor outstripped his enemies in the speed of his preparations. Whereas the Austrians believed he would not be able to reach the Danube in force before November 10th, he intended to have 200,000 men in Germany by September 18th. But he knew not at first the full extent of his good fortune: it did not occur to him that the Austrians would cross the Inn: all he asks Talleyrand, on August 23rd, is that such news may appear in the "Moniteur" as will gain him twenty days and give General Bertrand time to win over Bavaria, while "I make my 200,000 men pirouette into Germany." On August 29th the Army of England became the Grand Army, composed of seven corps, led by Bernadotte, Marmont, Davoust, Soult, Lannes, Ney and Augereau. The cavalry was assigned to Murat; while Bessières was in command of the Imperial Guard, now numbering some 10,000 men.
Already the greater part of this vast array was beginning to move inland; Davoust and Soult left some regiments, 30,000 strong, to guard the flotilla, and Marmont detached 14,000 men to defend the coasts of Holland; but the other corps on September 2nd began their march Rhine-wards in almost their full strength. On that day Bernadotte broke up his cantonments in Hanover, and began his march towards the Main, on which so much was to turn. The Elector of Hesse-Cassel now espoused Napoleon's cause. Thus, without meeting any opposition, Bernadotte's columns reached Würzburg at the close of September; there the Elector of Bavaria welcomed the Marshal and gave him the support of his 20,000 troops; and at that stronghold he was also joined by Marmont.
In order to mislead the Austrians, Napoleon remained up to September 23rd at St. Cloud or Paris; and during his stay appeared a Senatus Consultum ordering that, after January 1st, 1806, France should give up its revolutionary calendar and revert to the Gregorian. He then set out for Strassburg, as though the chief blows were to be dealt through the passes of the Black Forest at the front of Mack's line of defence; and, to encourage that general in this belief, Murat received orders to show his horsemen in the passes held by Mack's outposts, but to avoid any serious engagements. This would give time for the other corps to creep up to the enemy's rear. Mack, meanwhile, had heard of the forthcoming junction of the French and Bavarians at Würzburg, but opined that it threatened Bohemia.[26]
Accordingly, he still clung to his lines, contenting himself with sending a cavalry regiment to observe Bernadotte's movements; but neither he nor his nominal chief, the Archduke Ferdinand, divined the truth. Indeed, so far did they rely on the aid of the Russians as to order back some regiments sent from Italy by the more sagacious Archduke Charles; but 11,000 troops from Tyrol reached the Swabian army. That force was now spread out so as to hold the bridges of the Danube between Ingolstadt and Ulm; and on October 7th the Austrians were disposed as follows: 18,000 men under Kienmayer were guarding Ingolstadt, Neuburg, Donauwörth, Günzburg, and lesser points, while Mack had about 35,000 men at Ulm and along the line of the Iller; the arrival of other detachments brought the Austrian total to upwards of 70,000 men. Against this long scattered line Napoleon led greatly superior forces.[27] The development of his plans proceeded apace. Though Prussia had proclaimed her strict neutrality, he did not scruple to violate it by sending Bernadotte's corps through her principality of Ansbach, which lay in their path. He charged Bernadotte to "offer many assurances favourable to Prussia, and testify all possible affection and respect for her—and then rapidly cross her land, asserting the impossibility of doing anything else." Accordingly, that Marshal was lavish in his regrets and apologies, but ordered his columns to defile past the battalions and squadrons of Prussia, that were powerless to resent the outrage.[28]
The news of this trespass on Prussian territory reached the ears of Frederick William at a critical time, when the Czar sent to Berlin a kind of ultimatum, intimating that, even if Prussia deserted the cause of European independence, Russian troops must nevertheless pass through part of Prussian Poland. Stung by this note from his usually passive demeanour, the King sent off an answer that such a step would entail a Franco-Prussian alliance against the violators of his territory, when the news came that Napoleon had actually done at Ansbach what Alexander had announced his intention of doing in the east. The revulsion of feeling was violent: for a short space the King declared he would dismiss Duroc and make war on Napoleon for this insult, but in the end he called a cabinet council and invited the Czar to come to Berlin.[29]
While the Gallophil counsellors, Haugwitz and Lombard, were using all their arts to hinder the Prusso-Russian understanding, the meshes were being woven fast around Mack and the Archduke Ferdinand. Bernadotte's corps, after making history in its march, was detached to the south-east so as to hold in check the Russian vanguard, and to give plenty of room to the troops that were to cut off Mack from Austria, a move which may be compared with the march of Bonaparte to Milan before he essayed the capture of Melas. Both steps bespeak his desire to have ample space at his back before circling round his prey.
On October 6th the corps of Soult and Lannes, helped by Murat's powerful cavalry, cut the Austrian lines on the Danube at Donauwörth, and gained a firm footing on the right bank. Over the crossing thus secured far in Mack's rear, the French poured in dense array, and marched south and south-west towards the back of the Austrian positions, while Ney's corps marched to seize the chief bridges over the Danube.