The Holy Grail is most commonly identified as the Chalice of the Eucharist, the cup that Christ drank out of at The Last Supper and which was later used by Joseph of Arimathea to catch the blood of Jesus at his crucifixion. Less commonly, it is identified with the dish of the Pascal lamb that Jesus and his Apostles ate at The Last Supper.
The Cistercian chronicler Helinandus mentioned a vision shown to a hermit concerning the dish used by Christ at the Last Supper. The Hermit in turn wrote a latin text named "Gradale". This is where some confusion arises as if Helinandus had meant the Chalice, surely he would have written that the Hermit was shown a vision of the chalice, not the dish. However, if the hermit was shown a vision of a dish, why write a book called "Gradale" (grail, cup). Other spellings include "Greal", "Graal", "Greel" and "Grail". The explanation of "San Greal" (great dish) as "Sang real" (kingly blood) did not emerge until the later Middle Ages. Other etymologies that could have been passed over at the time are now obsolete.
Literary Tradition: The French Romances
French Grail romances were written between 1180 and 1240. According to the Catholic Encyclopedia they can be divided into two categories; (1) those concerned with the quest for the Grail and (2) those concerned with the history of the Grail.
Of the first class is the "Conte del Graal" of Chrestien de Troyes, a foremost 12th century poet. The "Conte de Graal" is a vast poetic compilation of some 60,000 verses. Another French romance was "Parzival" by Wolfram von Eschenbach. This text was based upon one of De Troyes unfinished pieces, "Perceval, ou Le Conte du Graal". Of The Welsh folk-tales, "Mabinogion" is undoubtably the most well known. The English poem "Sir Percyvelle," of the fifteenth century is also well known, although its writing is generally not considered of the same standard as those previously mentioned. Of the Early History versions the oldest is the metrical trilogy of Robert de Boron, composed between 1170 and 1212, of which only the first part and a portion of the second are in existence.
The most detailed history of the Grail is in the "Grand St. Graal" from the first half of the thirteenth century, where we are told that Christ Himself presented the book concerning this history to a pious hermit.
In the Early History versions the Grail is invested with the greatest sanctity. It is explained that the dish from which Christ ate the Paschal lamb, or the Chalice from which he drank his wine (depending on the particular version of the legend) passed into the possession of Joseph of Arimathea, and was used Joseph to gather the Precious Blood of the Lord, when His body was taken from the Cross.
Literary Tradition: The Grail and Joseph of Arimathea
As mentioned, the Grail Legend is closely intertwined with the legends of Joseph of Arimathea. As the story goes, Joseph was thrown into prison by the Jews, but was able to use the Grail to sustain himself for 42 years until his liberation. The legend has two versions; (1) that Jesus appeared to Joseph and gave him the Grail after he was imprisoned or (2) that Joseph still had the Grail following the crucifixion. Joseph's involvement in the Grail legend also higlights many of the mythological food producing properties of the Grail.
After Joseph's liberation, the Grail is then brought to Britain, either By Joseph himself and his son, Josephes (as told in "Grand St. Graal") or by Alian and one of his kin (as told in "Robert de Boron"). Galaad or Perceval, depending on the literary text, finally achieves the quest. However, upon his (Perceval or Gallad's) death the Grail vanished.
Origins of the Legend
In these texts, the legend appears to be in an advanced state of development. We know of no preceeding phases and therefore the history of the legend can only be conjectured. There are not only Christian parallels, but also Celtic and Oriental. The Oriental parallels such as; the persian cup of Jamshid, the Hindu Paradise, Cridavana and the Sun table of the Ethiopians, fail to be convincing.
The Celtic tradition on the other hand has far more reliable arguments in its favour. Both the Perceval legend, as well as the King Arthur legend are of Celtic origin. Various talismans and powerful or mystical trinkets feature strongly in Celtic folklore and often take the shape of magic lances, bowls or food-giving vessels (the clearest representation of the Grail as a food-giving vessel can be found in the Joseph of Arimathea legend). If one believes that the Grail legend has Celtic origins, then it would appear that "Mabinogion", with its simpler story of vengeance through talismans without much religious significance, would be the version nearest to the original form of the legend. Thus the religious element is a secondary one that occurred when the revenge tale was fused with that of Joseph of Arimathea
The Catholic Church, The Church of England and The Legend of The Holy Grail
Some state that the legend of Joseph of Arimathea, where he and his son bring the Grail, the most sacred and powerful religious icon to England, is essentially a legend of the conversion of Britain. This view is supported by the fact that only one clerical writer, Helinandus, writes of the Grail and the Catholic Church prefered to ignore the legend completely, although the cup of Christ remains an important part of the Eucharist. The Catholic Church's refusal to acknowledge the legend is quite acceptable considering that there are elements that are clearly not canonical. Furthermore it has a basis in apocryphy, not scripture.
However, possibly the most decisive obstacle between the Catholic Church and the acknowledgement of the Grail legend is the fact that the legend claims an illustrious and independant origin for the Church of England. It would not be suprising then if the legend of the Holy Grail was manipulated and contorted so that it could encourage separatist tendencies within Britain. It would be able to do this easily, especially when one remembers that written texts were rare and public opinion was swayed through folklore and the oral tradition. This explanation would also provide an explanation for the relatively late orgins of the legend of the Holy Grail.
Sources and Further Reading
http://www.geocities.com/Paris/5339/graal.html - looks at the literary tradition of the Grail.
www.newadvent.org - The Catholic Encyclopedia. Gives a thorough coverage of all the issues covered here and more. The coverage maybe slightly biased at some points though
www.greatdreams.com/arthur.htm - a look at the Arthuruan legends involving the Grail. Something not well covered in this node.
historymedren.about.com/od/holygrail - links to sites that cover the literary tradition surrounding the Holy Grail
www.rosslyntemplars.org.uk/holy_grail.htm and www.timelessmyths.com/arthurian/grail - more literary tradition and folklore surrounding the Grail
Other Highly dubious (and untrue) but interesting "sources"
The Da Vinci Code by Dan Brown
Monty Python and the Holy Grail by Monty Python