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 Altmuehl, 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 Massena 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