What killed Napoleon's army? Scientists find clues in DNA from fallen soldiers' teeth

...In October, Napoleon called his soldiers back after barely engaging the Russian army. It wasn't a defeat, but it was no win either. And during the march home, winter arrived early.

"They started to die of cold, hunger, and also infectious diseases," says Rascovan. All told, hundreds of thousands perished.

And in a new study published in the journal Current Biology, Rascovan and his colleagues say those diseases likely include two unexpected pathogens that would have helped hasten the soldiers' demise.