For gamers interested in the historical King Arthur, Arthuriana offers an interesting site.
Britons
Valiant Britons
Valiant Britons is Jim Wallman’s contribution to wargaming ancient british tribes in the pre Roman era. Its designed for 15mm figures, but he says that any scale will do. Like all of Wallman’s rules sets, it’s well done and makes me want to start painting the period immediately.