[1][2] The story is based on the medieval English tale Sir Gawain and the Green Knight and also Yvain, the Knight of the Lion by Chrétien de Troyes and the tale of Sir Gareth in Thomas Malory's Le Morte d'Arthur.
[3] Locations used included castles at Cardiff, Caerphilly and Castell Coch, Wales; Peckforton castle, Cheshire; and St Michael's Mount and Roche Rock, Cornwall.
Weeks remade the film in 1984 as Sword of the Valiant with Miles O'Keeffe and Sean Connery as Gawain and the Green Knight, respectively.
The mysterious Green Knight appears before King Arthur's court in the New Year and demands the head of Sir Gawain as the prize in a bizarre game.
Given a year's grace, Gawain sets off in search of the Knight for a rematch.