In the Battle of Mohrungen, most of a First French Empire corps under the leadership of Marshal Jean-Baptiste Bernadotte fought a strong Russian Empire advance guard led by Major General Yevgeni Ivanovich Markov. The French pushed back the main Russian force, but a cavalry raid on the French supply train caused Bernadotte to call off his attacks. After driving off the cavalry, Bernadotte withdrew and the town was occupied by the army of General Levin August, Count von Bennigsen. After demolishing the army of the Kingdom of Prussia in a whirlwind campaign in October and November 1806, Napoleon's Grande Armée seized Warsaw. After two bitterly fought actions against the Russian army, the French emperor decided to place his troops into winter quarters. However, in wintry weather, the Russian commander moved north into East Prussia and then struck west at Napoleon's left flank. As one of Bennigsen's columns advanced west it encountered forces under Bernadotte. The Russian advance was nearly at an end as Napoleon gathered strength for a powerful counterstroke.