Holy Grail, a feature of medieval legend and literature. It appears variously as a chalice, a cup, or a dish and sometimes as a stone or a caldron into which a bleeding lance drips. It was identified by Christians as the chalice of the Last Supper brought to England by St. Joseph of Arimathea. Miraculous in its powers, it could provide food and healing. However, it would be revealed only to a pure knight, and the Grail Quest appears in different stories. In Arthurian legend the purest knight is variously Parsifal or Galahad. The Grail is one of the most difficult problems of Arthurian legend, introducing as it does features of Christian story, Celtic myth, and ancient fertility cults.
See R. S. Loomis, The Grail (1963); E. Jung and M.-L. von Franz, The Grail Legend (tr. 1971).