St Fagan's name appears as "Phagan" (Medieval Latin: Phaganus) in William of Malmesbury's work On the Antiquity of the Glastonbury Church,[2] written between 1129 and 1139.
[3] It is given as "Fagan" (Faganus) in Geoffrey of Monmouth's pseudo-historical History of the Kings of Britain,[4] written around 1136 and sometimes supposed to have been the source of the name's later insertion into William's account.
[5] The name has been variously connected with Latin paganus ("rural, pagan"), French faguin ("faggoter, wood gatherer"), and Old English fagin ("joyful").
[7] The entry on Pope Eleutherius in Petrus de Natalibus's late 14th-century collection of saints' lives gives Fagan's name as "Fugatius",[8] an emendation subsequently copied by Platina[9][10] and many others.
[16][17] However, the work On the Antiquity of the Glastonbury Church,[2] initially written by William between 1129 and 1139,[5][18] and Geoffrey of Monmouth's History of the Kings of Britain[4][19] both include the names of Fagan and his companion.
A contemporaneous or even earlier source is the letter of the convent of St David's to Pope Honorius II preserved in Gerald of Wales's c. 1203 Book of Invectives[20][21] which appears to date from the 1120s.
[citation needed] The discrepancy in William's accounts led Robinson to conclude that the appearance of the missionaries' names in the earlier book was a spurious addition by the abbey's scribes, of a piece with the passages in the present text that include a patently fraudulent "Charter of St Patrick", that describe Abbot Henry of Blois (d. 1171) as "of blessed memory", and that mention a fire which occurred at the abbey in 1184.
Instead, Gerald's letter from the clerics at St David's says that Fagan and "Duvian" were the first apostles of all Britain, baptising its king Lucius and then converting all his subjects after their arrival in 140.
[20][21] Geoffrey also treats Fagan and "Duvian" as the first apostles to Britain, noting their conversion of Lucius's petty kings and success at "almost" removing paganism from the whole island until the Great Persecution under Diocletian.
He states that the pagan temples were remade into churches and 28 "flamens" and 3 "archflamens" were replaced by 28 bishops under the 3 archbishops of London (over Loegria and Cornwall), York (over Deira and Albania), and Caerleon (over Wales).
)[3] A fourth lists the following triplet among the "Sayings of the Wise":[33] Arguing in favor of a partial historicity to these figures, Rees noted that all but Elfan had long-standing associations with parish churches in the area around Llandaff, though he admitted none seemed as grand or preëminent as one might expect were they actually the apostles of Britain.
)[36] The 16th-century antiquarian John Leland recorded in his travel notebooks that a nearby chapel remained dedicated to Fagan and was sometimes also used as the parish church,[37] but this was in ruins by the time of the English Civil War a century later.
[citation needed] The festival of St Fagan does not appear in any surviving medieval Welsh calendar of the saints,[3] but he had some importance following his description as an apostle: the Blessed John Sugar, martyred in 1604, invoked "Fugatius" and "Damianus" from the gallows as authorities for the antiquity of British Catholicism.