It is now necessary to trace more particularly the incidents which had taken place on the extreme flanks of Napoleon's line of advance, on both of which, as we have already intimated, the Russians, powerfully reinforced, had assumed the offensive, with the apparent purpose of forming a communication with each other, and acting in conjunction, to intercept the retreat of the grand army. Upon the 18th of August, St. Cyr having beaten Witgenstein, and taken Polotsk, the war had languished in that quarter. The French army lay in an intrenched camp, well secured with barracks for shelter, and fortifications for defence. But in the partisan war which they carried on for two months, St. Cyr's army sustained great loss, while that of Witgenstein was more than doubled by the arrival of recruits. Finally, General Steingel, with two divisions of the Russian army from Finland, amounting to 15,000, landed at Riga, and after some inefficient movements against Macdonald, marched to the support of Witgenstein. The Russian general, thus reinforced, began to act on the offensive with great vigour. On the 17th of October, the French outposts were driven into their intrenched camp at Polotsk. On the 18th, the camp itself was furiously attacked, and the redoubts by which it was protected were taken and retaken several times. The French remained in possession of them, but St. Cyr was wounded, and his situation became very precarious. In fact, the next day, 19th October, the attack was renewed by Witgenstein on the right bank of the Dwina, while Steingel, advancing up the opposite bank, threatened to occupy Polotsk and its bridge, and thus to enclose St. Cyr in the intrenched camp.