"The piece which follows has never been published before(1979). There are only two surviving manuscripts of it, one a garbled copy and the other a summary, and it is only distantly connected with other versions of King Arthur's death. The most likely explanation for its existence lies in the brief and mysterious account which Geoffrey of Monmouth and his imitators gave of Arthur's death. The piece is headed 'This is the true history of Arthur's death', and the closing words lead into the chapter of Geoffrey of Monmouth's book which follows Arthur's death, as though the story was intended to replace the end of Geoffrey's account by a fuller and more explicit version. It is included here as a reminder that anyone was at liberty to invent a variation on the 'accepted' story of Arthur, though very few of these variations have actually survived.

The main manuscript in which the story is found is fourteenth-century, and probably came from North Wales, but beyond this it is difficult to say when the story was written. There are details in it which echo the romance version of Arthur's death as told by Malory. However, they are distant echoes: here Arthur is killed by adder's venom, in Malory an adder is the cause of the great last battle; here Arthur's tomb appears miraculously in the place where he was to be buried, in Malory the tomb materialises miles from where he was last seen alive; in both, Arthur is buried at a hermitage. Other details come from Celtic tradition; there was a widespread belief that Arthur was still alive, which Geoffrey hinted at my making him go to the mysterious isle of Avalon, and which we know of from a number of twelfth-century writers. However, the discovery of Arthur's supposed grave at Glastonbury in 1191 had severely shaken belief in this idea, and it would be tempting to say that the present story, which does not mention Glastonbury as the site of the tomb but puts his burial firmly in Gwynedd, was earlier than 1191. But the Glastonbury discovery was not accepted as genuine by everyone, and the writer could simply have ignored it.

Other parts of the narrative seem to be taken from the world of Welsh romance as found in The Mabinogion. For instance, the thunder and mist which descends on Arthur's body is not unlike an episode in the story of Pryderi, when Pryderi and his wife Rhiannon are laid under a spell.

A bowl and fountain are associated with a violent storm in a French romance based on Celtic stories, Chrétien de Troyes' Yvain, and the disappearance of Arthur's body could have come from a more elaborate version of Pryderi's enchantment. Equally, though there is no exact parallel, the young man with his elm lance could be a magical figure from Welsh romance. Arthur's devotion to the Virgin Mary could be taken from The History of the Britons. The general style of the piece is ambitious in its language, and points to a well-educated cleric as the author. Such, in brief, are the few scraps of evidence we have about this curious fragment, which, because of the complex phrasing of the which the original, is presented here in a fairly free translation."