Lugus

For the Philippine municipality, see Lugus, Sulu.

Lugus (sometimes Lugos^[1] or Lug^[2]: 123) is a Celtic god whose worship is attested in the epigraphic record. No depictions of the god are known. Lugus perhaps also appears in Roman sources and medieval Insular mythology.

The long dedication to Lugus from Peñalba de Villastar

Various dedications, concentrated in Iberia and dated to between the 1st century BCE and the 3rd century CE, attest to the worship of the god Lugus. However, these predominately describe the god in the plural, as the Lugoves. The nature of these deities, and their relationship to Lugus, has been much debated. Only one, early inscription from Peñalba de Villastar, Spain is widely agreed to attest to Lugus as a singular entity. The god Lugus has also been cited in the etymologies of several Celtic personal and place-names incorporating the element "Lug(u)-" (for example, the Roman settlement Lugdunum).

Julius Caesar's description in his Commentaries on the Gallic War of an important pre-Roman Gaulish god (whom Caesar identified with the Roman god Mercury) has been interpreted as a reference to the god Lugus. Caesar's description of Gaulish Mercury has been examined against Insular sources, as well as the prominence of "Lug(u)-" elements in Gaulish place-names. A prominent cult to Mercury in Roman Gaul may provide more evidence for this identification.

Lugus has also been connected with two figures from medieval Insular mythology. In Irish mythology, Lugh is an important and supernatural figure. His description as a skilled artisan and founder of a harvest festival has been compared with Gaulish Mercury. In Welsh mythology, Lleu Llaw Gyffes, a protagonist of the Fourth Branch of the Mabinogi, is a more minor figure, but is linked etymologically with Irish Lugh. He perhaps shares with the Lugoves an association with shoemaking.

The reconstruction of a pan-Celtic god Lugus from these details, first proposed in the 19th century by Henri d'Arbois de Jubainville, has proven controversial. Criticism of this theory by scholars such as Bernhard Maier has caused aspects (such as a pan-Celtic festival of Lugus on 1 August) to be abandoned, however scholars still defend the reconstruction.

Etymology

The etymology of Lugus's name has been the subject of repeated conjecture, but no single etymology has gained wide acceptance.^[3]: 211

The most commonly repeated etymology derives the name from proto-Indo-European *leuk- ("to shine"). This etymology is closely tied to proposals to identify Lugus as a solar god. However, Garrett Olmsted has pointed out that this derivation poses phonological difficulties. Proto-Celtic *lug- cannot develop from proto-Indo-European *leuk-, according to the known sound changes between the two languages.^{[4]: 181–183} Carlos Jordán Cólera [ca] has noted that this root would result in Irish Luch, rather than the attested Irish Lugh.^[5]: 918

Heinrich Wagner [de] and Erich Hamp have proposed that the name derives from a proto-Celtic word meaning "oath" (either *lugiom or *leugh-). John T. Koch has taken this hypothesis up, and proposed that the early Irish oath tongu do dia toinges mo thúath is a suppressed oath to Lugus.^{[6]: 252 [7]: 244} A. G. van Hamel and Maier proposed a derivation from proto-Celtic *lugus ("lynx"), perhaps used allusively to mean "warrior", but an article by John Carey found the evidence for the existence of such a word in proto-Celtic lacking.^[8][9]: 66 Other etymologies derive "Lugus" from the name of the Norse god Loki,^[3]: 211 proto-Celtic *luc- ("mouse" or "rat"),^[10] and Gaulish lougos ("raven").^[11]: 53

Linguistic evidence

Epigraphy

Text	Image	Context	Language	Citation	Comments
LUGOVIBUS / SACRUM / L(UCIUS) L(ICINIUS?) URCI/CO(M) COLLE/GIO SUTORU/M D(ONUM) D(EDIT)		Inscribed on an altar. Found in the Roman city of Uxama Argaela, near Osma, Soria, Spain.[12]: 213	Latin	CIL II, 2818	Translated, the inscription reads "Consecrated to the Lugoves. Lucius L(icinius?), of the Urcici donated it on behalf of the College of Shoemakers".[12]: 213  Connected to a trait of Welsh Lleu, discussed below.[13]: 71
DIBUS M(AGNIS ?) / LUCOBO(S) AVE(or NE) / T?ORIA AVITA / E? / CON EX VISU / CONSULENTIB(US)[a]		Inscribed on a stele. Found in Peña Amaya [es], Burgos, Spain.[12]: 213 [14]: 212	Latin	CIL II, 6338v	This poorly preserved inscription has been interpreted by Jürgen Untermann as a dedication to the Lugoves made, as a result of a vision, by a person with the cognomen Avita. Above the inscription is an ithyphallic figure with his arms outstretched (in orant position).[12]: 213 [14]
LUGUBO / ARQUIENOB(O) / C(AIUS) IULIUS / HISPANUS / V(OTUM) S(OLVIT) L(IBENS) M(ERITO)		Inscribed on an altar. Found in the church of San Martín de Liñarán in Sober, Lugo, Spain.[12]: 212	Latin	IRPL 67	Translated, the inscription reads "To the Luguves Arquieni, with all merit. Caius Iulius Hispanus in fulfilment of a vow".[12]: 212
SACRUM / LUCOUBU / ARQUIENI(S) / SILONIU(S) / SILO / EX VOTO		Inscribed on an altar. From the town of Sinoga in Rábade, Lugo, Spain.[12]: 211	Latin	IRPL 68	Translated, the inscription reads "Dedicated to the Lucouves Arquieni. Silonius Silo in fulfilment of a vow".[12]: 211
LUCOBO / AROUSA(BO?) / V(OTUM) S(OLVIT) L(IBENS) M(ERITO) / RUTIL[IA] / ANTIANIA		Inscribed on an altar. Found in a 2nd-century CE religious building in the city of Lugo, Spain.[12]: 209	Latin	AE 2003, 00951	Translated, the inscription reads "To the Lucoves Arousae, with all merit, Rutilia Antiania, in willing fulfilment of her vow".[12]: 209
LUC(OBO) GUD/ AROVIS? / VALE[RIUS?] / CLEM[ENS?] / V(OTUM) L(IBENTER) S(OLVIT)		Inscribed on an altar. Found in a 2nd-century CE religious building in the city of Lugo, Spain.[12]: 209	Latin	AE 2003, 00952	Translated, the inscription reads "To the Lucoves Gudarovi(?), Valerius (?) Clemens (?) in willing fulfilment of his vow".[12]: 209
[LUCU]BU / ARQ(U)IE / NIS [---] / IULIU(S) [---] V(OTUM) S(OLVIT)		Inscribed on an altar. Found in San Vicente de Castillón [es], Lugo, Spain.[12]: 212	Latin	BRAH 1971 185.	Translated, the inscription reads "To the Lucuves Arquieni(...) Iulius (...) in fulfilment of a vow".[12]: 212
RUFINA / LUCUBUS / V(OTUM) S(OLVIT) L(IBENS) M(ERITO)		Inscribed on a stele. Found in Nemausus (Roman Nîmes), Gard, France.[12]: 213	Latin	CIL XII, 3080
LUGOVES		Inscribed on a Corinthian capital. Found in the Roman city of Aventicum, near Avenches, Vaud, Switzerland.[15]: 594	Latin	CIL XIII, 5078	Karl Zangemeister suggested that the inscription referred to the figure originally set on the capital.[15]: 594
ΛΟΥΓΟΥϹ (translit.: lougous)		Inscribed on a ceramic dish. Found in the Oppidum de l'Ermitage [fr], in Alès, Gard, France.[16]	Gaulish	RIG I G-159	The inscription is probably an ownership mark, so at most records a theophoric personal name.[16]
[...] bissiet lugedessummiiis luge / dessumíis lugedessumiis luxe		Inscribed on a lead tablet. Found in Chamalières, Puy-de-Dome, France.[17]	Gaulish	RIG II.2 L-100	At the end of the Chamalières tablet inscription, luge dessumiis is repeated three times. This feature is very difficult to interpret, but Karl-Horst Schmidt [de] has interpreted it as an incantation of Lugus (in the singular). This interpretation has not been widely accepted.[17][4]: 88
ENIOROSEI / VTA.TIGINO.​TIATVMEI / TRECAIAS.​TOLVGVEI / ARAIANOM.​COMEIMV / ENIOROSEI.​EQVOISVIQVE / OGRIS.​OIOCAS.​TO.​GIAS.​SISTAT.​LVGVEI.​TIASO / TOGIAS[b]		Inscribed on a rock. Found at the site of Peñalba de Villastar, in Villastar, Aragon, Spain.[18]: 624	Celtiberian	MLH IV K.3.3	This inscription, which dates to the 1st century BCE and is among the longest found in the Celtic sanctuary of Peñalba de Villastar, is very obscure in its meaning. No definite translation of this text has been established, but the majority of scholars hold that to luguei is to be interpreted as a dedication to Lugus (in the dative singular).[5]: 914 [18]: 626 [c]
l.o.C(o).o.P(o).​n.i.i.a.r.​a.P(o).o [...][d]		Inscribed on a stele. Found in the Roman necropolis of Fonte Velha [pt], in Bensafrim, Lagos, Portugal.[20]: 203–204 [18]: 204	Tartessian	MLH IV J.1.1	The beginning of this inscription has been interpreted by José A. Correa as referring to Lugus in the dative plural (Locobo Niirabo).[12]: 213 [20] Jürgen Zeidler [de] has expressed scepticism about this reading.[21]

A number of dedications to Lugus, dating between the 1st century BCE and 3rd century CE, have been found in Continental Europe.^[22]: 190 This epigraphic data is concentrated in Iberia; only a small number of inscriptions are known from Gaul, and none are known from Britain or Ireland.^{[15]: 593–594} A peculiarity of this data is that the singular of Lugus's name is rarely recorded.^[12]: 215 There is consensus that a Celtiberian inscription from Peñalba de Villastar features the singular.^{[4]: 353–354} A minority interpret the Gaulish-language Chamalières tablet as invoking singular Lugus.^{[4]: 354 [12]: 214} The singular is inscribed on a ceramic sherd from Oppidum de l'Ermitage [fr], but this is probably a theophoric name and not a reference to the god Lugus.^{[4]: 353 [16]} Many Celtic gods are referenced both in the plural and the singular,^[e] but in dedications to Lugus the plural form ("Lugoves" or "Lucoves"^[f]) predominates.^[7]: 309

The nature of the Lugoves, and their relationship to Lugus, has been much debated.^[22]: 179 The epigraphic record is equivocal as to the gender of these deities. The epithet Arquienob(o) (attested at San Martín de Liñarán) has masculine gender, whereas the epithets Arousa(bo) (attested on an altar from Lugo) and possibly Niirabo indicate the feminine.^[12]: 215 Henri Gaidoz contended that plural deities were minor in the Celtic pantheon, and that therefore Lugus could not have been the chief god of the Celts. Arbois de Jubainville and Joseph Vendryes argued that the Celts invoked even major gods (such as Mars) in the plural.^{[4]: 354–355} Some scholars have tried to explain the multiplicity of the Lugoves through traits of Irish Lugh or Welsh Lleu.^{[12]: 214 [11]: 51–52} Marie-Louise Sjoestedt, for example, pointed out that Lugh was one of triplets.^[9]: 83 Maier has argued that the obscurity of the nature of the Lugoves limits the value of the epigraphic record as evidence for pan-Celtic Lugus.^[24]: 128 Krista Ovist argues against this point.^{[4]: 353–355}

Proper names

The element "lug(u)-" appears frequently in Celtic proper names. In many of these cases, an etymology involving the deity-name Lugus has been proposed.^{[25]: 219 [19]: 132} Celtic personal names with this element include Lug, Lugaunus, Lugugenicus, Lugotorix, Luguadicos, Luguselva, and Lougous.^[25]: 220 A number of cognate names are known from Irish Ogham inscriptions, for example, Luga, Lugudecca (perhaps, "serving the god Lugus"^[26]: 248), Luguqritt (perhaps, "poet like Lugus"^[27]: 221), and Luguvvecca.^[25]: 220 Some ethnic names have been connected with Lugus, for example the Lugi in Scotland^[19]: 58 and the Lugones [gl] in Asturias.^[19]: 63 Place-names connected with Lugus include Lugii, Lougoi, Lougionon, Lugisonis, and Lugnesses.^[25]: 221 Lucus Augusti (modern-day Lugo) is the site of a Roman sanctuary with dedications to the Lugoves;^[12]: 216 its name may be derived from the deity-name Lugus, though it could simply be Latin for "grove of Augustus".^[28]: 219 The name of Luguvalium (modern-day Carlisle) is sometimes glossed as "wall of Lugus", but may instead derive from a personal name.^{[24]: fn 4 [19]: 213}

Lugdunum (modern-day Lyon) at the heart of Roman Gaul

Since Arbois de Jubainville argued for the connection, the place-name "Lugdunum" has frequently been connected etymologically with Lugus. The most famous known by this name is Lugdunum (modern-day Lyon) in the region of Gallia Lugdunensis,^[g] a Roman colony and among the most important cities of Roman Gaul.^{[29]: 244–245} The etymology of this place-name has been the subject of much conjecture. Following Arbois de Jubainville, the most widely held hypothesis analyses the name as Lugus + dunum ("fort"),^[h] that is, "the fortress of Lugus".^{[25]: 219–220} Many other etymologies have been given.^{[23]: 483–484} An ancient etymology derives it from a Gaulish word for raven.^[i] Attempts have been made to analyse it as *lugus ("luminous" or "clear") + dunum ("hill"), bolstered by a medieval etymology which gives the gloss mons lucidus ("shining mountain").^{[19]: 131 [25]: 219–220}

The place-name Lugdunum is attested, in its cognate forms, as the name of as many as twenty-seven locations.^{[19]: 132 [j]} Apart from Lyon, there is Lugdunum Convenarum (modern-day Saint-Bertrand-de-Comminges), Lugdunum Batavorum (near Leyden), Lugdunum Remorum (modern-day Laon), two Welsh places named Din Lleu (the order of the elements reversed),^{[29]: 244–245} and two cities of unclear location in North East England and Germania Magna.^{[19]: 509–510} The wide range and abundance of these place-names has been used to argue for the importance of Lugus.^{[4]: 355–356} Whatever the etymology, not all of these place-names must owe themselves a Celtic root. Lugdunum/Lyon was a major city, and other locations may have borrowed the name. Some two-thirds of the cognate place-names are attested only from the 10th century on; we know that Lugdunum Remorum had an older, native name (Bibrax) which was displaced in the 6th century.^{[24]: 129–130}

Caesar and Gaulish Mercury

Altar from Reims to Apollo, Cernunnos, and Mercury

Commentaries on the Gallic War is Julius Caesar's first-hand account of the Gallic Wars (58 to 50 BCE). In giving an account of the customs of the Gauls, Caesar wrote the following:

Deum maxime Mercurium colunt. Huius sunt plurima simulacra: hunc omnium inventorem artium ferunt, hunc viarum atque itinerum ducem, hunc ad quaestus pecuniae mercaturasque habere vim maximam arbitrantur. Post hunc Apollinem et Martem et Iovem et Minervam. De his eandem fere, quam reliquae gentes, habent opinionem.^[31]

The god they reverence most is Mercury. They have many images of him, and they regard him as the inventor of all arts, the god who directs men on their journeys, and the most powerful helper in trading and getting money. Next to him they reverence Apollo, Mars, Jupiter, and Minerva, about whom they have much the same ideas as other nations.^{[32]: 33–34}

Caesar here employs the device of interpretatio romana, in which foreign gods are equated with those of the Roman pantheon.^[k] With very few exceptions, Roman writings about Celtic and Germanic religion employ interpretatio romana, but the equations they made varied from writer to writer. This makes identifying the native gods behind the Roman names very difficult.^{[33]: 203–204} Indeed, if their information was confused or their intention was propagandistic, reconstruction of native religion is next to impossible.^{[33]: 206–207}

Caesar contrasts Gaulish Mercury with the other gods of the Gauls, insofar as he is the god about whom they do not have "much the same ideas" as the Romans. The Romans associated Mercury with trading and travel, but they did not think of him as "inventor of all arts".^[24]: 132 Another difference is suggested by the order in which the gods are presented: Mercury is given primacy, whereas the Romans considered Jupiter the most important deity.^[33]: 206 Moreover, Mercury's role as guide of souls to the underworld (an important aspect of the god for the Romans) goes unmentioned in this passage. Caesar elsewhere ascribes to the Gauls a belief in metempsychosis, which may have precluded Gaulish Mercury from this function.^{[24]: 134 [l]}

The first Celtic god to be identified as Caesar's Gaulish Mercury was Teutates.^[m] This identification was widely accepted until the late 19th century, when Arbois de Jubainville proposed that Lugus lay behind Caesar's description. Arbois de Jubainville pointed to the prominence of "Lug(u)-" elements in Gaulish place-names, and a possible festival of Lugus at Lugdunum/Lyon (discussed below). He also drew comparison between Irish Lugh's epithet Samildánach ("master of all arts") and Caesar's description of Gaulish Mercury as "inventor of all arts".^[24]: 127 Maier has criticised this identification on the basis that "inventor of all arts", though not a Greco-Roman belief about the god Mercury, is a common literary topos in Roman descriptions of foreign religions. He also casts doubt on the possibility that an epithet like this, not otherwise attested in the epigraphic record, could have survived into medieval Irish literature.^{[24]: 132–134}

A confusing aspect of Caesar's description of this cult is his reference to the "many images" of Gaulish Mercury; specifically he uses the word simulacra, a word which had the connotation of worshipped idols for Roman authors.^[36]: 40 Archaeological evidence of anthropomorphic cult images is scant before the Roman conquest of Gaul.^[33]: 205 The testimony of some Roman authors suggests the Gauls did not produce images of their gods, though Lucan describes the Gauls as having wooden idols.^{[36]: 39–40} Salomon Reinach suggested that Caesar meant to draw a comparison between aniconic monuments to Gaulish Mercury and the herms (aniconic monuments to Hermes, Mercury's Greek equivalent) he knew from Rome, but this is an unlikely use of the word simulacra.^{[33]: 205–206 [36]: 42}

Inscription from Langres deo Mercur(io) Mocco ("to Mercury of the Swine")

Certainly, after Caesar's conquest of Gaul, depiction and worship of Mercury was widespread.^[n] More images of Mercury have been found in Roman Gaul than those of any other God,^[24]: 131 but these representations of Mercury are conventional, and show no discernible Celtic influence.^[34]: 537 Epigraphic material does reveal some bynames of Mercury peculiar to Gaul, thought to be suggestive of native gods.^[34]: 537 An inscription from Langres attests to a Mercur(io) Mocco ("Mercury of the Swine"), perhaps Lugus.^[37]: 98 Other epithets—connecting Mercury with heights, particular Gaulish tribes, and the emperor Augustus—have been thought to be suggestive of Lugus.^{[4]: 101–102 [7]: 316–318} The epigraphic record has not produced any epithets portraying Mercury as inventor or master of arts.^[24]: 134

Depictions

The Lyon cup

No images of Lugus are known.^{[2]: 23 [37]: 97} However, a number of figures have been proposed to represent Lugus. A Gallo-Roman silver cup from Lyon is decorated with a number of figures, including a human counting money next to a raven. Pierre Wuilleumier identified the human figure as Mercury/Lugus, whereas J.-J. Hatt [fr] identified the raven as Apollo/Lugus.^[2]: 143 Paula Powers Coe argued that the depiction of Mercury on an altar from Reims could be Lugus, as a rat (Gaulish lucot) is depicted above Mercury, perhaps punning on Lugus's native name.^[10]: 45 Arguing from an association between Irish Lugh and pigs, Gwenaël Le Duc [fr] has proposed that the Euffigneix statue (of a Gaulish boar-god) is a representation of Lugus.^[37]: 99

Later mythology

Lugh in Irish mythology

Lugh Lamfhota (literally, "Long-armed Lugh") is an Irish mythological figure from the Mythological Cycle and the Ulster Cycle. He is portrayed as a leading member of the Tuatha Dé Danann, a supernatural race in medieval Irish literature often thought to represent euhemerized pre-Christian deities. Alongside Fionn mac Cumhaill and Cú Chulainn (Lugh's supernatural son), he is one of the three great heroes of the Irish mythological tradition.^[38][39] The Irish celebrated Lughnasa, a harvest festival which fell on 1 August and which, according to Irish tradition, was established by Lugh in honour of his foster mother.^[40]

Arbois de Jubainville made the connection between Lugh and Lugus.^{[13]: 69–70} He adduced two connections between Irish Lugh and Celtic Lugus. Firstly, he drew attention to the (above discussed) correspondence between Lugh's epithet Samildánach ("master of all arts") and Caesar's description of Gaulish Mercury.^[24]: 127 Secondly, he pointed out that an annual concillium of the Gauls in Lugdunum/Lyon, instituted in 12 BCE in honour of the emperor Augustus, fell on exactly the same day as Lughnasa. He suggested that both must ultimately derive from a Celtic festival in honour of Lugus.^{[24]: 130 [41]: 111} Recent scholarship has tended to dismiss this as a coincidence.^{[4]: 515 [o]} Maier has pointed out that the Continental Celts used a lunar calendar, whereas the Irish used a solar calendar, so continuity of a seasonal festival would be unlikely.^[24]: 130

Lleu in Welsh mythology

The opening lines of the Fourth Branch of the Mabinogi

Lleu Llaw Gyffes (literally, "Lleu of the Skillful Hand" or "Steady Hand") is one of the protagonists of the Fourth Branch of the Mabinogi, a set of Welsh stories compiled in the 12th-13th centuries. He is a prince whose story culminates in him becoming ruler of Gwynedd.^{[13]: 68 [42]} Though not depicted as other than human, Lleu is depicted with extraordinary or magical skills, like many other characters in Welsh mythology.^[13]: 75 Lleu (or characters similar to him) appears in other works of medieval Welsh literature. Notable examples are Lluch Llavynnauc (Lluch "of the Striking Hand" or Lluch "Equipped with a Blade") in Pa gur; Lluch Lleawc (Lluch "the Death Dealing") in Preiddeu Annwn; and Llwch Llawwynnyawe (Lluch "of the Striking Hand") in Culhwch.^[13]: 69

John Rhys was the first to relate Lleu to Lugus, which he did in 1888. Rhys drew a comparison between an episode in the Mabinogi, wherein Lleu and his foster father Gwydion produce gold-ornamented shoes, and the inscription from Uxama Argaela, where the Lugoves are invoked by a group of shoemakers. This parallel has received a mixed reception.^{[13]: 70–71} Joseph Loth felt that the episode was minor and the conclusion extravagant.^{[43]: 297–299} Jan de Vries agreed with Rhys, and further argued that the "Lugoves" in this inscription were Lleu and Gwydion.^[11]: 52

Lugus-Lugh-Lleu?

Though the stories told of Lleu and Lugh do not show many similarities,^[13]: 75 comparisons have been drawn between epithets of Lleu and Lugh: Lleu is Llaw Gyffes ("of the Skillful Hand") and Lugh is Samildánach ("master of all arts"); Lleu is Llawwynnyawe ("of the Striking Hand") and Lugh is Lonnbémnach ("of the Fierce Blows").^[13]: 71 Ronald Hutton points out that medieval Welsh and Irish literature are known to have borrowed superficially from each other (for example, the similar in name but dissimilar in character Welsh Manawydan fab Llŷr and Irish Manannán mac Lir). This would suffice to explain the common epithets.^[13]: 75

Welsh Lleu and Irish Lugh are both linguistically correct as reflexes of a Gaulish or Brittonic name Lugus.^[13]: 70 Hutton notes that a medieval borrowing cannot explain the linguistic relationship between Lugh and Lleu. For the names to be cognate, their common origin must be prior to the respective sound changes in Irish and in Welsh.^[13]: 75 Jessica Hemming argues that, insofar as Lugus is entirely absent from the epigraphic record in Britain and Ireland, the etymology is questionable.^[44]: 102

Reconstruction

Henri d'Arbois de Jubainville

The god Lugus was first reconstructed by Arbois de Jubainville in his monumental Le cycle mythologique irlandais et la mythologie celtique (1884). Arbois de Jubainville linked together Irish Lugh, Caesar's Gaulish Mercury, the toponym Lugdunum, and the epigraphic evidence of the Lugoves. By 1888, Sir John Rhys had linked Lugus with Welsh Lleu.^{[13]: 70–71} Initial criticism of this theory (for example, from Henri Gaidoz) gave way to what Ovist has described as "uncritical affirmation" of the existence of a pan-Celtic god Lugus.^[4]: 66 Over the 20th century, the theory was further elaborated.^[13]: 71 The long inscription from Peñalba de Villastar was first published in 1942 and, by the 1950s, it had been identified as a unique dedication to Lugus in the singular.^{[15]: 595 [5]: 914} In a 1982 article, Antonio Tovar cited Lugus as an exemplar of the unity of ancient Celtic culture. Few other Celtic gods could be said to be attested in Gaulish, Insular, and Iberian sources.^{[15]: 592–593}

Early doubts about Lugus were raised by Pierre Flobert (in the 1960s) and Stephanie Boucher (in the 1980s).^[33]: 206 However, scepticism about the god only entered the mainstream in the 1990s, coinciding with a wave of scepticism about the unity of the ancient Celts.^[13]: 72 The most important of these critiques was mounted by Bernhard Maier, in his 1996 article "Is Lug to be Identified with Mercury?".^[13]: 72 As well as criticising the identification of Caesar's Gaulish Mercury with Irish Lugh, Maier cast doubt on the value of the previously adduced epigraphic and toponymic data from Continental Europe. As Ovist put it, Maier "in effect, question[ed] the very existence of Continental Lugus".^[4]: 353

Scepticism about the existence of Lugus has not become consensus.^[13]: 73 Recent monographs on the god by Krista Ovist (2004) and Gaël Hily (2012) have reaffirmed and elaborated on Arbois de Jubainville's reconstruction.^{[45]: 253–255} The strength of the epigraphic and toponymic evidence has been marshalled in defense of the hypothesis by scholars such as Ovist and Zeidler.^{[27]: 221 [4]: 355}

Notes

1. This reading follows Jürgen Untermann.^[12]: 213 A large number of other readings have been given, collected in an article by Ana María Vázquez Hoys.^{[14]: 214–216}
2. There are several readings of this inscription, but this reading follows Untermann, who gives the following variants: LVGVES for LVGVEI and OLOCAS for OIOCAS.^[18]: 624
3. Not all agree with this interpretation. Carlos Jordán Cólera interpreted luguei as "through an oath". Patrizia de Bernardo Stempel has argued against Jordán Cólera's hypothesis.^{[19]: 131–132} Untermann's suggested alternate reading, lugues, would give the name in the nominative plural, but (as Francisco Marco Simón points out) this is at odds with word to before it, which appears to be in the dative.^[12]: 214
4. This article only give the transliteration of this inscription, which is written in the Southwest Paleohispanic script. The reading given here follows José A. Correa.^[20]: 206 Untermann gives a different reading.^[18]: 208
5. Arbois de Jubainville was aware of this and compared Lugus/Lugoves to the pairs Deo Vitiri/Dibus Vitiribus and Deo Mounti/Dis Mountibus known from Roman Britain.^[4]: 355 Joshua Whatmough points out that this feature is common to Gaul as well, where plural dedications to Mercury, Epona, and Silvanus are known.^[23]: 196
6. Garrett Olmsted explains the form "Lucoves" as a result of "the tendency to confuse the voiced and unvoiced series, particularly c and g, [...] most frequent in Spain and Aquitania".^[7]: 309
7. The Roman province, which stretched from Saône to Brittany, took its name from the city.^[23]: 483
8. Gaulish dunun or dunum has the meaning "'citadel, fortified enclosure, mount".^{[3]: 154–155}
9. This etymology, reported in the 2nd-century text De fluviis, is given as part of a founding legend of Lugdunum/Lyon: two founders with Gaulish names observe ravens over a hill, and decide to found a city there, deriving its name from lougos ("raven") + dunun ("hill"). The gloss of dunun is correct, but the supposed Gaulish word lougos is a hapax legomenon and has no clear cognates in other Celtic languages, though Zeidler has proposed a derivation from proto-Indo-European.^{[27]: 215–216 [30]: 170}
10. Christian-Joseph Guyonvarc'h lists 27 places connected with this name. He classifies 20 as certain, 5 as probable, and 2 as doubtful.^[19]: 132 Alfred Holder gives a shorter list of 16 in his Alt-celtischer Sprachschatz.^[29]: 244
11. The equation of a Roman god with a foreign god was made on the basis of their perceived similarity, but, in practice, a clear equivalent was often absent, so one common trait or sphere of activity sufficed to justify the equivalence.^[33]: 203
12. Indeed, Gerhard Bauchhenss [de] has pointed out that depictions of Mercury are very rare on Gallo-Roman tombs, suggesting that this aspect of Mercury was never assimilated into Gaulish religion.^[34]: 547
13. Teutates, one of the few Celtic gods known by his native name in Roman literature, has been a candidate for the identity of Gaulish Mercury since medieval commentators on Lucan. This identification was reasserted in the 17th century by Elias Schedius and was repeated through most of the 18th and 19th centuries. In modern times, this identification has received the support of Jean-Louis Brunaux [fr].^{[35]: 200–201 [24]: 127}
14. Paul-Marie Duval [fr] estimated that two-thirds of all monuments in the Roman world dedicated to Mercury have been found in Gaul.^[15]: 593
15. There are a number of reasons 1 August may have been chosen for a festival in honour of Augustus: the month bore his name^[24]: 130 and the date was the anniversary of his political victory over Antony and Cleopatra.^{[41]: 111–113}