During Napoleon’s disastrous retreat from Russia in the bitter cold, his army of 600,000 men was decimated by starvation and disease. A new study identified which pathogens contributed to their demise.

In June 1812, Napoleon I invaded Moscow with 500,000 to 600,000 soldiers, hoping to conquer Russia. However, finding themselves isolated in a ruined city, they decided to retreat that fall, according to study’s authors. Little did they know, however, that the Russian winters would be more brutal than the enemy soldiers’