During the eighteen days that Buonaparte halted at Wilna he was actively employed in endeavouring to cut asunder the Russian host. Whilst Barclay de Tolly, under the Czar, commanded the main force, which had now fallen back from Wilna to Drissa, Prince Bagration was lying far to the south-east in Poland, at Volkovisk, with seven thousand Cossacks under Platoff at Grodno, and another body of men under Dorokhoff as far as Lida. Buonaparte ordered Murat, with his cavalry, to drive the rear of the main Russian army in the direction of Drissa. Murat was followed by a division of infantry, under Oudinot and Ney, whilst the King of Westphalia was ordered to advance eastward to cut off Bagration's division from all chance of junction with De Tolly, and Davoust was to attack him in the rear. He himself proposed to push forward between these bodies towards Vitebsk, and thus threaten both St. Petersburg and Moscow. By this arrangement he made himself sure of destroying Bagration's division, or compelling it to surrender. But contrary to his wont, Buonaparte was found not to advance with his usual rapidity; and the fact was that there were sufficient reasons for the delay. His supplies had failed already. The country, already impoverished by a bad harvest in the preceding year, was swept by the Russians of all possible provisions; and the vast horde of French, Germans, and Italians now advanced treading down the unripe corn of the present. Owing to the state of the roads, flooded by torrents of rain, the provision-waggons could not get along. Twenty thousand sick men had to be left behind wherever they could, for they had no good hospitals; and, in crossing Lithuania, one hundred thousand men fell from fatigue, from exhaustion, from surprises by the Cossacks, and from diseases which they brought with them. Bagration, prevented by Jerome of Westphalia from pursuing his route towards Drissa, changed his course towards Minsk; but finding himself outstripped there too, he made for the Beresina, and effected a passage at Bobruisk. He then ascended the Dnieper as far as Mohilev; but, finding himself anticipated by Davoust, he attacked that general in the hope of cutting his way through. In this he failed, after a sharply-contested engagement, and once more he retired down the Dnieper, and crossed at Nevoi-Bikoff, which enabled him to pursue his course for a union with Barclay de Tolly, who was making for Smolensk. Thus Bagration, though running imminent hazard of being cut off, managed to out-manœuvre Napoleon himself--a new event in his campaigns. On his march, his troops had several encounters with the French and Polish cavalry; but Platoff showed great gallantry, and often severely punished the enemy.