I found a Wikipedia article on the French archers I was talking about.

https://en.wikipedia.org/wiki/Franc-archer

It says they were archers and does not actually say they were Longbowman though but I think they probably were. And the Book that I read about it in the first place said they were Longbowmen(War Bows by Mike Loades, which is currently being used to raise up my computer monitor).