Earlier in the morning Dupont had proceeded with his column south and east along the river , from Marbach , according to instructions . Even before the arrival of Mortier 's courier , he heard the sound of artillery in the distance and sent riders ahead to discover the cause . They came back to report that a Russian column ( Dokhturov 's ) was descending from the mountains to take the road to Dürenstein . Realizing this would separate him from the forward division , Dupont hustled his troops toward the sound of battle and deployed them to take the Russians in the flank . The French assault , heralded by cannon fire , caused Dokhturov 's troops to turn their attention from Gazan 's beleaguered force to face these new assailants . Although superior in numbers , Dokhturov 's column had no supporting artillery , and the narrow space prevented them from taking advantage of their size . It was Dokhturov 's turn to face attackers at his front and rear , until the arrival of Schmitt 's column , which had wended its way through the mountains in the west .