In both cases the romance follows the prose rendering of Borron's Joseph of Arimathea and Merlin, and precedes a Mort Artus, thus forming part of a complete cycle.
When the founding of the Round Table is ascribed to Merlin it is generally in close connexion with the Grail legend, forming the last of a series of three, founded in honour of the Trinity - the first being the table of the Last Supper, the second that of the Grail, established by Joseph of Arimathea, The number of knights whom the table will seat varies; it might seat twelve or fifty or a hundred and fifty; nowhere, save in Layamon, do we find a practically unlimited power of accommodation.
The "sudario" from which it takes its name is asserted to be the shroud in which Joseph of Arimathea wrapped the body of Jesus.
The Glastonbury thorn, planted, according to the legend, by Joseph of Arimathea, has been the object of considerable comment.
According to the legends which grew up under the care of the monks, the first church of Glastonbury was a little wattled building erected by Joseph of Arimathea as the leader of the twelve apostles sent over to Britain from Gaul by St Philip. About a hundred years later, according to the same authorities, the two missionaries, Phaganus and Deruvianus, who came to king Lucius from Pope Eleutherius, established a fraternity of anchorites on the spot, and after three hundred years more St Patrick introduced among them a regular monastic life.