The hill of Lugdunum, modern Fourvière Hill (Colline de Fourvière), Lyon, France
Various theories have been proposed to account for the legend of King Lucius of Britain, who supposedly sent a letter to Pope Eleutherius of the late 2nd century asking to be converted to Christianity. None of them are particularly convincing. I would urge my readers to explore those, regardless. I do not feel sufficiently motivated to do so here.
To me, the solution to the mystery is fairly simple and straight-forward. To begin, we might take a look at two relevant entries from P.C. Bartrum's A WELSH CLASSICAL DICTIONARY:
LLEUFER MAWR.
‘The Great Light’. A gloss to §22 of the Historia Brittonum in the ‘Cambridge’ group of
manuscripts (Mommsen: C, L) says of Lucius, the fictitious king of Britain: Lucius, agnomine Leuer-
maur, id est, ‘magni splendoris’ propter fidem que in eius tempore venit. This was mentioned by Lewis
Morris in his Celtic Remains (p.270 s.n. Lles ap Coel), and he says “none of our writers in the British
tongue mention this cognomen of Lleufer Mawr”. But it was taken up later by Iolo Morganwg. See s.n.
Lucius.
[NOTE: The GPC entry for lleufer has the derivation of the word's first element as lleu(1), "light, brightness; bright." Lleu in Welsh is the god who corresponds to the Irish Lugh and the Gaulish Lugus. Lucius probably derives from Latin word lux (gen. lucis), meaning "light" (<PIE *leuk-, "brightness"), related to the Latin verb lucere ("to shine").]
LUCIUS, fictitious king of Britain. (A.D.165-208 PCB)
The earliest trace of Lucius as a king of Britain appears in an extract from the Liber Pontificalis
(known as the Catalogus Felicianus) drawn up between A.D.483 and 492 in which a letter is mentioned
from Lucius of Britain to pope Eleutherius. Under Eleutherius it says: A WELSH CLASSICAL DICTIONARY
487
Hic accepit epistolam a Lucio Britannio rege ut Christianus efficeretur per ejus
mandatum.
(LBS III.353). It seems to have been clearly proved by Dr.Harnach (Sitzungsberichte d.
k. Preuss. Akad. d. Wissenschaften, 19 Mai 1904) that this was a blunder caused by a confusion between
the local names Britannia and Britium, for the letter from Lucius to pope Eleutherius seems genuine, but
Lucius ruled in Edessa, not in Britain, and Birtha (Britium) was his citadel. His full name was Lucius
Aelius Septimius Megas Abgarus IX, king of Britium of the Edessenes, A.D.174-9. See also The English
Historical Review, xxii (1907), pp.767-70, OP II.670, LBS III.360, Oman pp.177-8, HW 103). The
mention in the Catalogus Felicianus looks like a late interpolation, as the earliest extant manuscript is of
the ninth century (LBS III.353-4). The story appears again more fully in the Liber Pontificalis about
A.D.685 (LBS III.356-7).
The story was unknown to Bede when he wrote his ‘De Temporibus’ in 702. Not until
725 when he wrote his ‘Chronicle’ does Bede show knowledge of it. He wrote:
A.161-180. M. Antoninus Verus [Marcus Aurelius] with his brother Aurelius
Commodus [Lucius Verus], for ten years and one month. ... His brother Commodus being dead, he
made Antoninus Commodus his son co-regent of the kingdom. ... Lucius king of Britannia sent a
letter to Eleutherus bishop of Rome asking that he might be made a Christian.
(LBS III.352). Lucius Verus died in 169, so that the implied date of the supposed letter is between
A.D.169 and 180. Eleutherius was bishop of Rome from 174/5 to 192. This narrows down the date of
the letter to the period 175-180 (LBS III.352). Later in 731 when Bede wrote his ‘Ecclesiastical History’
he entered (I.4):
In the year from our Lord's incarnation 156, Marcus Antoninus Verus ... was made emperor,
together with his brother, Aurelius Commodus. In their time whilst Eleutherius, a holy man,
presided over the Roman church, Lucius, king of the Britons, sent a letter entreating that by his
command he might be made a Christian. He soon obtained his pious request, and the Britons
preserved the faith which they had received, uncorupted and entire, in peace and tranquility until
the time of the emperor Diocletian.
Again in his chronological summary at the end of his history he wrote (V.24):
In the year from the incarnation of our Lord, 167, Eleutherius, being made bishop of Rome,
governed the church most gloriously fifteen years. Lucius king of Britain, writing to him, requested
to be made a Christian, and succeeded in obtaining his request.
Note the discrepancy in date which is explained in LBS III.353.
This was copied in the Historia Brittonum (§22):
After one hundred and sixty-seven years from the advent of Christ, Lucius, the British king, with
all the rulers of the whole of the British race, received baptism, an embassy having been sent by the
emperor of the Romans and by the Roman pope Eucharistus (so H, but Evaristus M, Eleutherius
CGLQ and Lebor Bretnach).
There is a gloss in C and L as follows:
Lucius, agnomine Leuer-maur, id est, 'magni splendoris', propter fidem que in eius tempore
venit (Mommsen, p.164, l.23, n.6).
On this name see s.n. Lleufer Mawr.
Between the years 1125 and 1130 the Chapter of St.Andrew and St.David (at Menevia)
addressed an extraordinary letter to pope Honorius II, asserting that their church had been the seat of an A WELSH CLASSICAL DICTIONARY
488
archbishop since the first beginnings of Christianity in Britain, i.e. the days of pope Eleutherius, who
had sent to king Lucius the preachers Fagan and Duvian and founded three archbishoprics and 27
bishoprics in the kingdom. (The only source of this letter is Giraldus Cambrensis, De Invectionibus,
II.10, ed. W.S.Davies, in Cy. 30 (1920) pp.143-6). (This is not in the Rolls edition, No.21 Vol.3). It
seems to be the first to mention Fagan and Duvian. Giraldus wrote De Invectionibus in about 1203.
(Christopher Brooke in Studies in the Early British Church, ed. Nora K.Chadwick, 1958, pp.207-8).
Geoffrey of Monmouth began to clothe the bare legend with detail in his Historia Regum
Britanniae (c.1136). We are told that Coillus [Coel] had but one son, Lucius [Lles], who obtained the
crown after his father's death, and imitated all his acts of goodness. He sent letters to pope Eleutherius,
desiring to be instructed by him in the Christian religion, and obtained the accomplishment of his pious
request. For the pope sent him two most religious doctors, Faganus [Ffagan] and Duvianus [Dwywan],
who preached the Word of God, and baptized him. Then people from all countries assembled together
and followed the king's example. The holy doctors, having almost extinguished paganism over the whole
island, dedicated the temples, that had been founded in honour of many gods, to the one only God and
his saints. The twenty-eight pagan flamens were replaced by twenty-eight bishops, and the three
archflamens were replaced by three archbishops at London, York and Caerleon [Caerllion ar Wysg]
(HRB IV.19). Lucius permitted the possessions and territories which formerly belonged to the temples
to be appropriated to Christian churches, and gave them all kinds of privileges. He died in Gloucester
and was buried there in the cathedral church in the year 156. He had no issue to succeed him (HRB V.1).
Brut y Brenhinedd tells much the same story, but omits mention of the ‘flamens and
archflamens’. Corresponding names are shown in [ ].
At about the same time (c.1150) the compilers of the Book of Llandaf produced a somewhat
different story (BLD 68):
In the year of our Lord 156 Lucius Britannorum rex sent his ambassadors Eluanus and
Meduuinus to Eleutherius ... imploring that he might be made a Christian, according to his
admonition; to which request he acceded; for giving thanks to God that the nation, which from the
first inhabiting by Brutus had been heathens, so ardently desired to embrace the faith of Christ, he,
with the advice of the elders of the Roman city, was pleased to cause the ambassadors to be
baptized. On their embracing the Catholic faith, Eluanus was ordained a bishop, and Meduuinus a
doctor. Through their eloquence and the knowledge which they had acquired in the holy scriptures,
they returned as preachers to Lucius in Britain. By their holy preaching Lucius and the nobles of
all Britain received baptism.
See further s.nn. Elfan and Medwin.
It is noteworthy that this is the first introduction of Christianity to Britain known to Geoffrey of
Monmouth or to the compilers of the Book of Llandaf. Soon after they wrote, however, legends were
beginning to grow concerning earlier preachings of the Gospel. As a result it was said that the request by
Lucius to pope Eleutherius was rather to revive the faith than to introduce it for the first time. See s.n.
Joseph of Arimathea.
FURTHER FICTIONS
Many details were added later to the fable. John Stow said that the Church of St.Peter, Cornhill,
London, was founded by Lucius, and he mentions a ‘table’ in that church testifying to this. He also said
that according to Jocelyn of Furness the church of St.Peter, Cornhill, was built by Thean, first
archbishop of London, with the aid of Ciran, chief butler to king Lucius (The Annales of England, 1600
edition, p.37). Francis Godwin called the chief butler Cyranus (De Praesulibus, 1616, p.226).
Another fable became attached to Lucius, by mis-identification with a legendary saint Lucius of
Chur or Coire in Switzerland. The earliest ‘Life’ (8-9th cent.) is edited in MGH Hist.Rerum
Merovingicarum, III.1-7. See outline in LBS III.358-9. He is there said to have been a pagan king of A WELSH CLASSICAL DICTIONARY
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Britain, converted by Timothy, disciple of St.Paul. Migrated to Gaul and then to Chur. Later accounts
say that he died there on December 3. Finally he is said to have been martyred there. See LBS III.359.
When he was identified with the British king Lucius of Bede, his conversion by Timothy had to be
dropped.
John Bale (Scriptorum ... Catalogus, 1557, p.23) said that Lucius, king of Britain, was
accompanied by his sister Emerita. They were both killed near Curia [Chur] and were commemorated on
December 3 and 4 respectively. See James Usher, Britannicarum Ecclesiarum Antiquitates, 1687,
Chapters 3 and 6; Hugh Cressy, Church History, 1668, pp.67-70. On Emerita see also Thomas
Dempster, Hist.Eccles. Gentis Scotorum, 1627, no.482 = p.261.
A unique pedigree in Peniarth MS.128 (late 16th century), p.61, pretends that Coel of Colchester
(who is mis-identified with Coel Godebog) had a claim to the crown of Lloegr through Emerita.
‘Namely Coel ap Tegfan ap Dehevraint [Deheuwaint] ab Emerita ferch Coel ap Meurig, sister and
heiress of Lles, king of Britain.’ The implication is that Emerita was the wife of Telpwyll (q.v.). This is
a tour de force without any merit (PCB).
Iolo Morganwg introduced a further layer of fiction by re-naming Lucius as Lleirwg or Lleurwg
and giving him a new pedigree, making him son of Coel ap Cyllin (q.v.) ap Caradog ap Brân (e.g. Iolo
MSS p.115).
For some inexplicable reason, those seeking to identify King Lucius have not considered the following historical bit concerning Eleutherius:
"The early Christian writer St. Hegesippus says that Eleutherius was deacon of the Roman church under Pope St. Anicetus (c. 155–c. 166). Succeeding St. Soter as pope, Eleutherius ruled during the reign of Commodus (Roman emperor 180–192; coruler with his father, Marcus Aurelius, 176–180), who was relatively tolerant of the Christians. Eleutherius had been devoting close attention to the Montanist controversy when, in 177, Christians in the Lyon area wrote him expressing their opinion of the teachings of the prophet Montanus. Although the letter has been lost, it is believed to have asked Eleutherius to show mercy but not to compromise with followers of the movement. The churches of Lyon and Vienne, France, sent the letter by Bishop St. Irenaeus of Lyon, who was delegated to advise Eleutherius." [https://www.britannica.com/biography/Saint-Eleutherius]
Now, Lyon is the ancient Roman Lugdunum. The most likely etymology for the Lugdunum place-name is "the fort of Lugus." Lugdunum was the capital of the province of Gallia Lugdunensis, which included in its territory Armorica/Brittany (https://www.britannica.com/place/Lugdunensis).
I would add in passing that the original name of the Roman Arbeia fort at South Shields in Northern England was Lugudunum (https://romaninscriptionsofbritain.org/inscriptions/1054). Wales has its own Dinas Dinlleu (the city of the fort of Lleu) and a couple other sites in Britain may have similar or identical names (including, in my opinion, Lothian and Loudon).
To me, then, it is a rather simple matter to see in the 6th century mention of Lucius of Britain sending a letter to Pope Eleutherius the people of the Fort of Lugus/Lyon sending their letter to the same pope. Brittany of Gallia Lugdunensis was mistaken for Britain. It is also possible that some folk memory of the pan-Celtic deity Lugus/Lleu/Lugh helped fuse Britain and Brittany into this slightly garbled account of Christian intervention in the spread of the Monanist heresy.
Lucius might well be a Christian substitution for Lugus.
The letters 'c' and 'g' are frequently interchangeable in early medieval manuscripts. This phonetic and scribal blurring is a direct result of how the Latin language evolved into Romance languages and how local vernacular languages adapted the Latin alphabet.
Why 'C' and 'G' interchanged:
1) Visual Similarity: In late Roman cursive and early medieval scripts (like Merovingian, Visigothic, or Insular minuscule), an uncial or lowercase 'c' and 'g' could look remarkably alike. A slight slip of the pen or a faint stroke could easily turn a c into a g (or vice versa) during transcription.
2) Shared Phonetic Origins: Both letters represent velar consonants. In Classical Latin, 'C' originally represented both the /k/ and /g/ sounds (which is why the abbreviation for the Roman name Gaius is written as C.). While the Romans later added a stroke to 'C' to create 'G' for the voiced sound, the two remained tightly linked phonetically.
3) Palatalization: As Latin transitioned into early medieval Romance dialects, both 'c' and 'g' underwent "palatalization" when placed before the vowels e and i. This softened their sounds (e.g., 'c' sounding like "ch" or "ts", and 'g' sounding like "j" or "y"), making them sound much closer to one another than they did in classical times.
4) Vernacular Influences: Scribes in regions like Ireland, Britain, and Germany were adapting Latin letters to spell entirely different native Germanic or Celtic sounds. In Insular script, for instance, the lenition (softening) of consonants meant that 'c' and 'g' often represented a spectrum of shifting guttural or aspirate sounds, leading to highly variable spellings in both local languages and regional Latin.
One quick example of Luc- for Lug- is found in going from Irish Lugh to Welsh Llwch. This is from P.C. Bartrum's A WELSH CLASSICAL DICTIONARY:
"LLWCH LLAW-WYNNIOG. (Legendary).
He is mentioned twice in the tale of ‘Culhwch and Olwen’, first as Lloch Llaw-wynnyawc, one
of the chiefs at Arthur's Court (WM 461, RM 107), and later as Llwch Llaw-wynnyawc, the father of un-
named sons ‘from beyond the Tyrrhene Sea’, also apparently at Arthur's Court (WM 466, RM 110).
He is also mentioned in the poem ‘Who is the Porter?’, a dialogue between Arthur, Cai and
Glewlwyd Gafaelfawr in the Black Book of Carmarthen (BBC 94) as Lluch llauynnauc, ‘Llwch of the
Striking Hand(?)’ who was ‘defending Eidyn on the border(?)’ (Trans. Rachel Bromwich in The Figure
of Arthur by Richard Barber, 1972, p.70).
The translation of the cognomen by Gwyn Jones and Thomas Jones is 'Windy-hand' (The
Mabinogion, Everyman edition, pp.101, 104), but Idris Foster suggested ‘of the striking hand’
(Arthurian Literature in the Middle Ages, ed. R.S.Loomis, 1959, p.34). The name equates to that of the
Irish god, Lug, one of whose epithets was lonnbémnech, ‘of the fierce blows’."
A Gaulish Lucudeca in Ranko Matasovic's AN ETYMOLOGICAL DICTIONARY OF PROTO-CELTIC:
"*Lugu- ‘god Lug’, perhaps originally ‘the shiny one’ [Noun]
GOID: OIr. Lug [PN], Ogam L UGU-DECCAS W: MW Llew
GAUL: Lugus (e.g. RIG G-159)
CELTIB: LUGUEI [Dat. s] ( Penalba)
ETYM: Cf. the parallelism of the compound PNs OIr. Lugaid (Gen Luigdech ), Ogam LUGUDECCAS (CIIC no. 263) and Gaul. Lucudeca ‘serving the god Lug’ < PCelt. *Lugu-dek-s (Uhlich 2002: 409). For the second element of this compound see PCelt. *dekos.
REF: EIEC 97, Delamarre 211, Jordan Colera 1998: 63, 207ff, Uhlich 2002: 409, Ziegler 1994: 112, Kalygin 2006: 102ff., Sims-Williams 2006: 86, MLH V.l: 235f."
I've found Lucdunum for Lugdunum:
"https://net.lib.byu.edu/~catalog/people/rlm/latin/l/lugduni.htm
https://www.columbia.edu/acis/ets/Graesse/contents.html
Lugdunum
Peddie: Lyon
Graesse II:424 (Lugdunum, Augusta Lugdunensis, Laudunensis, Leo, Leudunum, Leunum, Lugdinum, Lugdona, Lugdonensis, Lugdonon, Lugdunensis, Lugduninsis, Lugdunum Celtarum, Lugdunum Galliae, Lugdunum Galliarum, Lugdunum Segusianorum, Lugudinum, Lugudunum
=Lyon, Hst. d. Dép. Rhône, Frankreich.)
Graesse II:433 (Lutum, Lugdunensis, Lugdunum, Lugium, Lugum, Luvensis
=Louth sw. Dundalk, Co. Louth (Lubhaidh), Rep. Irland, (Eire).)
Graesse II:354 (Laudunum, Laudensis, Laudunensis, Laudunum Clavatum, Laonensis civ., LUCDUNUM, Ludunensium castrum, Lugdunum, Lugdunum Clavatum, Lugdunum Glavatum, Lugdunum Cloade, Mons Lauduni
=Laon, Hst. d. Dép. Aisne (Ile de France), Frankreich.)"
"Another early medieval folk-etymology of the name, found in gloss on the Latin poet Juvenal [in William of Conches (c. 1090 – c. 1154) Glosae in Iuvenalem] connects the element Lugu- to the Latin word for "light", lux (luci- in compounds) and translates the name as "Shining Hill" (lucidus mons).[11]"
[11]"Lugdunum est civitas Gallie quasi lucidum dunam, id est lucidus mons, dunam enim in Greco mons." in Andreas Hofeneder, Die Religion der Kelten in den antiken literarischen Zeugnissen: Sammlung, Übersetzung und Kommentierung, Volume 2, Austrian Academy of Sciences Press, 2008, pp. 571–572 (in German).
Other examples can doubtless be found that adequately demonstrate how Lugdunum could have come to be perceived as Lucius' fort/hill.
Whenever we can link legend to history, rather than to some wholly imaginary construct, the principle of Occam's Razor demands that we adopt the former method and not the latter.




