One of the all-time great westerns
Ok, so it is set in East Anglia but that doesn't stop it from basically being a British western. All those shots of a vengeful Ian Ogilvy charging through the countryside on his horse!
It remains a truly disturbing film, the scenes of the "witches" being killed have lost none of their power since the film was released. Price makes an excellent villain in what is, I think, his best performance. Ogilvy is no less impressive as the man driven by, and ultimately overtaken by, pure rage.
I can't think of many better revenge westerns offhand. There's the Eastwood revenge trilogy obviously (Outlaw Josey Wales, High Plains Drifter, Unforgiven). But I would say this film is as key to British cinema as The Searchers is to American cinema. It really is that good.