Quote Originally Posted by ThePianist View Post
Napoleon (and I read this as a little kid in another language, so I am not sure whether it's accurate or not) was the one who invented a formation of three row deep, first row lay down, second row kneel, and third row standing. First row fire while second and third rows reload, then second row fire while first and third rows reload, and then third row fire while first and second reload, and so on. Then it was adopted by the other nations during the Napoleonic Wars. Maybe that's why there are mostly rows of threes.
Rank-and-File formation, I believe thats called. I'm not sure about the kneeling/laying down, since that would make it rather difficult to reload. I'm pretty sure the Chinese were the first to use the idea, though. Napoleon may've been the first to make it popular, however. I'm not sure.
The three-man-deep line formation was in use long before Napoleon. I think it was Frederick the Great who made it famous, but people'd been using it for a while, even by then.