What is the secret of the Grail?' So intoned a heavenly voice to Sir Percival in John Boorman's stylish and influential film 'Excalibur' (1981). The sacred allure of the Holy Grail has fascinated writers and ensnared knights for over a thousand years. From Malory to Monty Python, the eternal chalice - said to be the very cup from which Christ drank at the Last Supper - has the richest associations of any icon in British myth. Many different meanings have been devised for the Grail, which has been linked to the Celts and King Arthur, the eucharistic rites of Eastern Christianity, ancient mystery religions, Jungian archetypes, dualist heresies, Templar treasure and even the alleged descendants of Christ himself and Mary Magdalene. The common thread running through all these stories is the assumption that the Grail legend has a single source with a meaning that - if only we could decode it - is concealed in the romances themselves. That meaning has become the subject of coded, secret documents and is the central feature of a vast conspiracy supposedly stretching back to the dawn of western civilization. Juliette Wood here reveals the elusive and embedded significance of the Grail story in popular consciousness - as myth, medieval romance, tangible holy relic and finally as the centre of an esoteric theory of global conspiracy. The author shows how various interpretations of the Grail, over the centuries, reflect changing cultural needs and desires. Her book will enthral those who, like Sir Percival, seek to unlock the mysterious secrets of western mythology's most extraordinary and tantalising enigma, and will delight students of history, myth and religion alike.