After departing from Moscow on October 18 with 100,000 combat-ready but undersupplied troops, Napoleon's strategic object was to quarter his army for the winter at the closest French supply depot, which was at Smolensk, to the west. Kutuzov had forced Napoleon after the Battle of Maloyaroslavets to retreat northwest over Mozhaisk to Smolensk on the devastated route of his advance that he had wished to avoid. During the three-week march to Smolensk, however, the Grande Armée was devastated by a combination of factors: starvation, demoralization, breakdown in troop discipline, a crippling loss of horses and essential supplies, attacks from the Russian army, constant harassment by its Cossack irregulars and partisans.