The result of Napoleon’s activity and the supineness of his foes were soon apparent.  Danzig surrendered to the French on May the 24th, and Neisse in Silesia a little later; and it was not till the besiegers of these fortresses came up to swell the French host that Bennigsen opened the campaign.  He was soon to rue the delay.  His efforts to drive the foe from the River Passarge were promptly foiled, and he retired in haste to his intrenched camp at Heilsberg.  There, on June the 10th, he turned fiercely at bay and dealt heavy losses to the French vanguard.  In vain did Soult’s corps struggle up towards the intrenchments; his men were mown down by grapeshot and musketry:  in vain did Napoleon, who hurried up in the afternoon, launch the fusiliers of the Guard and a division of Lannes’ corps.  The Muscovites held firm, and the day closed ominously for the French.  It was Eylau over again on a small scale.

But Bennigsen was one of those commanders who, after fighting with great spirit, suffer a relapse.  Despite the entreaties of his generals, he had retreated after Eylau; and now, after a day of inaction, his columns filed off towards Koenigsberg under cover of the darkness.  In excuse for this action it has been urged that he had but two days’ supply of bread in the camp, and that a forward move of Davoust’s corps round his right flank threatened to cut him off from his base of supplies, Koenigsberg.[130]

The first excuse only exposes him to greater censure.  The Russian habit at that time usually was to live almost from hand to mouth; but that a carefully-prepared position like that of Heilsberg should be left without adequate supplies is unpardonable.  On the two next days the rival hosts marched northward, the one to seize, the other to save, Koenigsberg.  They were separated by the winding vale of the Alle.  But the course of this river favoured Napoleon as much as it hindered Bennigsen.  The Alle below Heilsberg makes a deep bend towards the north-east, then northwards again towards Friedland, where it comes within forty miles of Koenigsberg, but in its lower course flows north-east until it joins the Pregel.

An army marching from Heilsberg to the old Prussian capital by the right bank would therefore easily be outstripped by one that could follow the chord of the arc instead of the irregular arc itself.  Napoleon was in this fortunate position, while the Russians plodded amid heavy rains over the semicircular route further to the east.  Their mistake in abandoning Heilsberg was now obvious.  The Emperor halted at Eylau on the 13th for news of the Prussians in front and of Bennigsen on his right flank.  Against the former he hurled his chief masses under the lead of Murat in the hope of seizing Koenigsberg at one blow.[131] But, foreseeing that the Russians would probably pass over the Alle at Friedland he despatched Lannes to Domnau to see whether they had already crossed in force.  Clearly, then, Napoleon did not foresee what the morrow had in store for him:  his aim was to drive a solid wedge between Bennigsen and the defenders of Koenigsberg, to storm that city first, and then to turn on Bennigsen.  The claim of some of Napoleon’s admirers that he laid a trap for the Russians at Friedland, as he had done at Austerlitz, is therefore refuted by the Emperor’s own orders.