Baring-Gould’s sources: Mentioned in English Martyrologies, and by Ferrarius in his General Catalogue of the Saints. The evidence for these Saints is purely traditional; the first written record of them was by Gildas, a.d. 560, but his account is lost. It is referred to by Matthew of Westminster.
Saint Elvan of Avalon, or Glastonbury, was brought up in that school erroneously said to have been founded by S. Joseph of Arimathea. He vehemently preached the truth before Lucius, a British king, and was mightily assisted by S. Mydwyn of Wales (Meduinus), a man of great learning. Lucius despatched Elvan and Mydwyn to Rome, on an embassy to Pope Eleutherius, in 179, who consecrated Elvan bishop, and appointed Mydwyn teacher. He gave them, as companions, two Roman clerks, Faganus and Deruvianus; or, according to some, Fugatius and Damianus. They returned with these to King Lucius, who was obedient to the word of God, and received baptism along with many of his princes and nobles. Elvan became the second archbishop of London. He and Mydwyn were buried at Avalon. S. Patrick [apostle of Ireland (5th century)] is said to have found there an ancient account of the acts of the Apostles, and of Fugatius and Damianus, written by the hand of S. Mydwyn. Matthew of Westminster gives the following account of the conversion of Lucius, under the year 185:—"About the same time, Lucius, king of the Britons, directed letters to Eleutherius, entreating him that he would make him a Christian. And the blessed pontiff, having ascertained the devotion of the king, sent to him some religious teachers; namely, Faganus and Deruvianus, to convert the king to Christ, and wash him in the holy font. And when that had been done, then the different nations ran to baptism, following the example of the king, so that in a short time there were no infidels found in the island."
There is a considerable amount of exaggeration in this account of Matthew of Westminster, which must not be passed over. Lucius is known in the Welsh triads by the name of Lleurwg, or Lleufer Mawr, which means "The great Luminary," and this has been Latinized into Lucius, from Lux , light. He was king of a portion of South Wales only. The Welsh authorities make no mention of the alleged mission to Rome, though, that such a mission should have been sent, is extremely probable. Some accounts say that Medwy and Elfan were Britons, and that Dyfan and Ffagan (Deruvianus and Faganus) were Roman priests. But both these names are British, consequently we may conjecture that they were of British origin, but resided then at Rome.
Four churches near Llandaf bore the names of Lleurwg (Lucius), Dyfan, Ffagan, and Medwy, which confirms the belief in the existence of these Saints, and indicates the scene of their labours. Matthew of Westminster adds:—"A.D. 185. The blessed priests, Faganus and Deruvianus, returned to Rome, and easily prevailed on the most blessed Pope that all that they had done should be confirmed. And when it had been, then the before-mentioned teachers returned to Britain, with a great many more, by whose teaching the nation of the Britons was soon founded in the faith of Christ, and became eminent as a Christian people. And their names and actions are found in the book that Gildas the historian wrote, concerning the victory of Aurelius Ambrosius."
Geoffrey, of Monmouth, who, unsupported, is thoroughly untrustworthy, mentions the same circumstance, on the authority of the treatise of Gildas, now lost. The embassy to Rome shall be spoken of at length, under the title of S. Lucius, December 11th. See also Nennius, § 22; Bede [English monk and historian (d. 735)]'s Eccles. Hist. i. 4; and the Liber Landavensis, p. 65.
