The latter general made up his mind that the badly shaken morale of his army, no less than the Emperor’s interests, imperatively demanded a victory, and determined to give battle. But he was too wary to deprive himself of the advantage of allowing the Russians to waste their strength against his defensive position before himself taking the offensive. He therefore waited during the morning of the 18th for Wittgenstein to come on. The latter, on his side, having driven Oudinot again into Polotsk, decided to withdraw, his mission being to defend the St. Petersburg road, and greatly overestimating the strength of the force opposed to him. His troops were to commence their march at 9 p.m. St. Cyr during the morning made a parade of retiring his trains and reserve parks through the town towards Vitebsk, while Merle and Verdier were brought nearer to it as though to cover an evacuation. Some of the cavalry also defiled along the southern bank of the Düna with their horses laden with forage. These devices do not appear to have tricked the Russian staff into the belief that Polotsk was about to be abandoned; but they did give it the impression that there was no fear of an attack. The Russian army lay bivouacked in the order in which it had fought on the 17th, and head-quarters were at the hamlet of Prizmenitza, only half a mile from Spas. St. Cyr, finding that Wittgenstein did not show any sign of attacking, and doubtless marking the obvious unpreparedness of the Russians, decided to take the offensive. About 2 p.m. Verdier’s division began to cross the Düna, screened from the sight of the Russians by the houses of Polotsk and the high banks of the Polota. Merle, Doumerc, and Castex’s light cavalry followed. Meanwhile at Spas Deroy’s division relieved Wrede’s, and a battery of 31 guns was massed at the village. St. Cyr’s plan, as he defines it, was to smash Wittgenstein’s line by a heavy and concentrated attack of four infantry divisions advancing at the double, Wrede’s Bavarians leading on the right, Deroy to their left rear, Legrand and Verdier in echelon on the left of Deroy, while the cavalry followed in support, and Merle’s division stood in reserve at Polotsk. St. Cyr in his report to Berthier says that he had intended to commence the attack at 4 p.m., but the bringing up of the troops from the left bank of the Düna proved a tedious operation; and it was not until nearly 5 that St. Cyr was able to give the signal to commence the battle. The French and Bavarian artillery opened a tremendous cannonade against the unsuspecting Russians, with great effect, especially among two batteries in advance of Prizmenitza, which lost nearly all their horses, and had a number of guns and waggons disabled or blown up against the Bavarian artillery. Diebich skilfully placed some guns in a battery on the extreme Russian left, which, being masked, caused considerable loss, but could not silence the far stronger array of pieces ranged before Spas.