Arn The Knight Templar is a great film on the crusades. It was on Netflix recently might still be there and I believe there is also a sequel. Then, of course, there is Nicolas Cage in Seasons of the witch, and then maybe the best Robin Hood film out there from 1993 Robin Hood Men in Tights. It depends on what you are trying to achieve with your students. Arn would probably be the best for a historical lesson of sorts but you can't beat "We're men! We're men in tights. We roam around the forest looking for fights."