In the summer of 1812, French Emperor Napoleon Bonaparte led approximately 500,000 soldiers on a campaign to conquer Russia but suffered a devastating defeat. It is widely reported that a significant portion of the French army perished that winter.

EADaily, October 26th, 2025. Two unexpected pathogens were among the diseases that devastated Napoleon's vaunted Grand Army. This is reported by NBC with reference to the results of a new study published in the journal Current Biology.

DNA from Napoleonic soldiers’ teeth uncovered two fever-causing bacteria that may have worsened the army’s fatal retreat from Russia.