Napoleon's "Grande Armée" of 610,000 men invaded Russia, heading towards Moscow, in the beginning of summer on 24 June 1812. The Russian army retreated before the French and again burnt their crops and villages, denying the enemy their use. Napoleon's army was ultimately reduced to 100,000. His army suffered further, even more disastrous losses on the retreat from Moscow, which started in October. Multiple sources concur that winter and its aftermath was only a contributing factor to Napoleon's defeat and retreat.