The Cup of Christ
The best-known tales of Arthur — those of the quest for the Holy Gail — are much later. The origin and meaning of the tales have been debated and speculated upon in countless books. Like Arthur himself, they represent a curious merger of Celtic pagan legends and Christian symbolism. The cup that Arthur and his knights seek out is ostensibly the cup of Christ, present at the last supper, the emblem of the transformative eucharist.
The Quest for the Grail
The grail quest is actually a later addition to Arthurian tales although it is unquestionably drawn from the earliest stories of Arthur and other Celtic heroes and their search for the cauldron of illumination. The exact nature of the grail is also disputed, seen variously as an emblem of conversion, the realization of love, the neglected goddess of the land, or even the marriage bed of Christ. No matter how Christian the tale, however, it is clear the story has its roots in ancient Celtic quests for the cauldron of the gods. Both the cup and the cauldron are symbols of divine grace, emblems of rebirth and spiritual illumination.
Arthur's earliest quest is mentioned only briefly in early Celtic tales. In the enigmatic Welsh poem “The Spoils of Annwn,” Arthur is one of the seven heroes who return from the fruitless underworld quest for the cauldron of Annwn. The cauldron reappears in some versions of the story of Culwhch and Olwen, as one of the thirteen treasures collected for Olwen's dowry.
While the tale of the Holy Grail is Christian on the surface, it is deeply pagan underneath. One of the earliest tales of the Holy Grail is the unfinished grail romance of Chretien of Troyes, “Perceval, the Story of the Grail,” wherein the grail is the mysterious magical object through which the injury of the mysterious Fisher King can be healed. The injury of the king's groin is an obvious phallic symbol of the vitality of the land, symbolism with clear roots in the ancient connections of the king and the land, the living goddess through which the king's authority was derived. An important symbol of the goddess Sovereignty was a wine goblet, offered to the would-be king on the occasion of his betrothal to the goddess. Curiously, Arthur himself receives a similar wound in many stories.
By the time the grail is associated with Arthur and his knights, its symbolism has been transferred. It is now the cup of the Last Supper of Christ and his apostles, which, according to legend, was filled with Christ's blood at his crucifixion. The transition of the symbol from an emblem of the goddess to an emblem of Christ can be seen as an almost perfect analogy of the uneasy spiritual transition of the Celtic people — Christian on the surface, with a pagan heart and sensibility underneath.
The Goddess and the Grail
Many Arthurian researchers have tackled the multilayered Arthurian symbolism and concluded that in many cases, the story preserves the anxiety of a culture transitioning from a very dual system to a monotheistic outlook. The qualities once borne by the goddess now reside in the mother of Christ and many female saints, but the deeper symbolism of the goddess is represented by the grail.
Some see a clear parallel between the wounds of the Fisher King (and, later, in Arthur's injuries) and the fate awaiting a Celtic king who did not fulfill his marriage obligation to the goddess. Celtic kingship was wholly tied to the fertility of the land and the prosperity of its people. A king who was not righteous and fair, who did not accept the full responsibility of leadership, would see the land suffer barrenness and drought. Indeed, infertility is a persistent theme in Arthur's story. Although Arthur is a heroic and wise ruler, he is cursed. His wife can bear no heir, and the kingdom he has built is destined to fall to ruin at his death. Even more strangely, it is Arthur's son by his sister, whom he refuses to acknowledge, who becomes the instrument of his ruin.