In Search of the Holy Grail

One interesting story from the Middle Ages is the search for the Holy Grail. There are those who have claimed that behind it lies some mysterious, hidden brand of Christianity which is to be preferred to standard Christian orthodoxy. Is there any basis for this claim?

The Grail is part of the larger story of King Arthur. He was originally pictured as a British leader who fought the invading Anglo-Saxons. The earliest story seems fairly prosaic and straightforward, with a few embellishments, like Arthur's single-handed killing of large numbers of people and fighting with giants, and with exaggerations, such as his conquering most of Europe.  As time went on, Arthur's story accumulated various fanciful elements. Many of these seem to be derived from Celtic mythology. But while Arthur is portrayed as Christian, I see no trace in Arthur's story in general of an alternative form of Christianity.

The Grail seems to be one of the stories that attached itself to Arthur.  In the earlier versions, Arthur appears to be incidental, and the main protagonist is Percival.  The story has Percival as a young man whose father  is a knight who has been killed and whose mother has concealed the existence of knights from him to protect him. But he finds out about knights and, against his mother's pleading, sets out to become one.  In spite his initial ignorance, by persistence and natural ability he becomes a great knight and, in some versions, avenges his father or becomes a king. This is all a nice straightforward adventure story.  Mixed in with this are what appear to be elements of Celtic mythology, particularly a quest to restore the fertility of the land. A key element in this quest is an object variously pictured as a severed head, a cup, and a stone, all of which fit in well with Celtic mythology.

The interpretation of the cup as the one at the Lord's Supper seems to be an attempt to import a Christian symbol into an otherwise pagan story. The story does involve the importance of relics and an emphasis on Christ being physically present in the Eucharist, both good Roman Catholic doctrines of the time.  In the final version, Percival--and Galahad, who eclipses him--become monks. But I see nothing of some alternate form of Christianity. The obvious alternatives at the time, the Cathars and the Waldensians, were opposed to the Roman Catholic emphasis on the Eucharist and Christ's physical presence in it and would not have been comfortable with the Arthurian legend's chivalrous worldliness.

You can always read something in by creating an allegory, but I see no evidence of any hidden theology here.  Even supposing there was one, I see no reason for giving it precedence over what the Scripture and the Christian church have historically taught.  The fact it appears this late with no proven antecedents is highly suspect.  There is an attraction to knowing some arcane truth concealed through the ages, but is this really plausible?