He took the Sangreal's holy quest,
And slumbering saw the vision high
He might not view with waking eye."
In his note on this passage, he refers to the romance of the Morte Arthur, and says:
"One day when Arthur was holding a high feast with his Knights of the Round Table, the Sangreal, a vessel out of which the last Passover was eaten (a precious relic, which had long remained concealed from human eyes, because of the sins of the land), suddenly appeared to him and all his chivalry. The consequence of this vision was that all the knights took on them a solemn vow to seek the Sangreal."
The orthography of the word in the romance itself is Sancgreall, which affords us a clue to what I believe to be its true etymology, Sang réel (Sanguis realis), a name it derived from the tradition of its having been employed, not only to hold the paschal lamb at the Last Supper, but also by Joseph of Arimathea to catch the blood and water which flowed from the wounds of our Blessed Lord.
Archdeacon Nares, in his Glossary, pp. 209. 445., enters largely into the legendary history of the Sangreal, as well as the question of its orthography. He takes some pains to refute the etymology given above, and quotes Roquefort (Dict. de la Langue Romane) to prove that graal or greal signifies a broad open dish. Will any one who has the means of consulting Roquefort inform us, whether he brings forward any instance of the existence of such a word in this sense? or, if so employed, whether such use may not have arisen from the ordinary erroneous orthography? It is a question well worth investigation, which I hope may call some abler pens than mine into exercise.
This holy relic, the object of so much fruitless search to Arthur and his knights, is now safely deposited in the cathedral of Genoa, where all, holy or unholy, may behold it, on making the accustomed offering to its sanctity. Of old, it concealed itself from the eyes of all but those free from mortal sin; but now, the ability to pay five francs puts one in possession of every Christian virtue, and the Sacro Catino (as it is called) is exhibited on the payment of that sum. In addition to the authorities quoted by Nares, I would refer to Sir F. Palgrave, in Murray's Handbook to Northern Italy, 1st edition, p. 105.
Sa. Ca.