Names of the Celts
The name Κελτοί Keltoi and Celtae is used in Greek and Latin, respectively, as the name of a people of the La Tène horizon in the region of the upper Rhine and Danube during the 6th to 1st centuries BC in Greco-Roman ethnography. The etymology of this name and that of the Gauls Γαλάται Galatai / Galli is of uncertain etymology. The name of the Welsh, on the other hand, is taken from the designator used by the Germanic peoples for Celtic- and Latin-speaking peoples, *walha-, meaning foreign.
The linguistic sense of the name Celts, grouping all speakers of Celtic languages, is modern. In particular, aside from a 1st-century literary genealogy of Celtus the grandson of Bretannos by Heracles, there is no record of the term "Celt" being used in connection with the Insular Celts, the inhabitants of the British Isles during the Iron Age, prior to the 17th century.
The first recorded use of the name of Celts – as Κελτοί – to refer to an ethnic group was by Hecataeus of Miletus, the Greek geographer, in 517 BC, when writing about a people living near Massilia (modern Marseille). In the 5th century BC Herodotus referred to Keltoi living around the head of the Danube and also in the far west of Europe.
The etymology of the term Keltoi is unclear. Possible roots include Indo-European *k´el-‘to hide’ (also in Old Irish celid), IE *k´el- ‘to heat’ or *kel- ‘to impel’. Several authors have supposed it to be Celtic in origin, while others view it as a name coined by Greeks. Linguist Patrizia De Bernardo Stempel falls in the latter group, and suggests the meaning "the tall ones". 
The Romans preferred the name Gauls (Galli) for those Celts whom they first encountered in northern Italy (Cisalpine Gaul). In the first century BC Caesar referred to the Gauls as calling themselves Celts in their own tongue.
According to the 1st-century poet Parthenius of Nicaea, Celtus (Κελτός) was the son of Heracles and Keltine (Κελτίνη), the daughter of Bretannus (Βρεττανός); this literary genealogy exists nowhere else and was not connected with any known cult. Celtus became the eponymous ancestor of Celts. In Latin Celta came in turn from Herodotus' word for the Gauls, Keltoi. The Romans used Celtae to refer to continental Gauls, but apparently not to Insular Celts. The latter are divided linguistically into Goidels and Brythons.
Aside from the Celtiberians —Lusones, Titi, Arevaci and Pelendones among others— who inhabited large regions of central Spain, Greek and Roman geographers also spoke of a people or group of peoples called Celtici or Κελτικοί, living in the South of modern day Portugal, in the Alentejo region, between the Tagus and the Guadiana rivers. They are first mentioned by Strabo, who wrote that they were the most numerous people inhabiting that region. Later, the description of Ptolemy shows a more reduced territory, comprising the regions from Évora to Setúbal, being the coastal and southern areas occupied by the Turdetani.
A second group of Celtici was mentioned by Pliny living in the region of Baeturia (northwestern Andalusia); he considered that they proceeded "of the Celtiberians from the Lusitania, because of their religion, language, and because of the names of their cities".
In the North, in Galicia, another group of Celtici dwelt the coastal areas. They comprised several populi, including the Celtici proper: the Praestamarci south of the Tambre river (Tamaris), the Supertamarci north of it, and the Neri by the Celtic promontory (Promunturium Celticum). Pomponius Mela affirmed that all the inhabitants of the coastal regions, from the bays of southern Galicia and till the Astures, were also Celtici: "All (this coast) is inhabited by the Celtici, except from the Douro river to the bays, where the Grovi dwelt (…) In the north coast first there are the Artabri, still of the Celtic people (Celticae gentis), and after them the Astures." He also mentioned the fabulous isles of tin, the Cassiterides, as situated among these Celtici.
The Celtici Supertarmarci have also left a number of inscriptions, as the Celtici Flavienses did. Several villages and rural parishes still bear the name Céltigos (from Latin Celticos) in Galicia. This is also the name of an archpriesthood of the Catholic Church, a division of the archbishopric of Santiago de Compostela, encompassing part of the lands attributed to the Celtici Supertamarci by ancient authors.
Introduction in Early Modern literature
The name of the Celtae is revived in the learned literature of the Early Modern period. The French celtique and the German celtisch appear in the 16th century. The English word Celts is first attested in 1607. The adjective Celtic, formed after French celtique, appears a little later, in the mid 17th century. An early attestation is found in Milton's Paradise Lost (1667), in reference to the Insular Celts of antiquity: [the Ionian gods ... who] o'er the Celtic [fields] roamed the utmost Isles. (I.520, here in the 1674 spelling).
In the 18th century the interest in "primitivism", which led to the idea of the "noble savage", brought a wave of enthusiasm for all things "Celtic". The antiquarian William Stukeley pictured a race of "Ancient Britons" constructing the "Temples of the Ancient Celts" such as Stonehenge (actually a pre-Celtic structure) before he decided in 1733 to recast the "Celts" in his book as "Druids". The Ossian fables written by James Macpherson - portrayed as ancient Scottish Gaelic poems - added to this romantic enthusiasm. The "Irish revival" came after the Catholic Emancipation Act of 1829 as a conscious attempt to demonstrate an Irish national identity, and with its counterpart in other countries subsequently became known as the "Celtic revival".
The initial consonant of the English words Celt and Celtic can be realised either as /k/ or /s/ (that is, either hard or soft ⟨c⟩), both variants being recognised by modern dictionaries. A minor spelling variant Kelt, Keltic exists, for which /k/ is the only pronunciation.
The English word originates in the 17th century, taken from the Celtæ of classical Latin. Until the mid 19th century, the sole pronunciation in English was /selt/ in keeping of the treatment of the letter ⟨c⟩ inherited by Middle English from Old French and Late Latin.
Beginning in the mid-19th century, Celtic revivalist and nationalist publications advocated imitating the pronunciation of classical Latin in the time of Julius Caesar, when Latin Celtæ was pronounced /keltai/.
An early example of this is a short article in a November 1857 issue of The Celt, a publication of the Irish Celtic Union.
- "Of all the nations that have hitherto lived on the face of the earth, the English have the worst mode of pronouncing learned languages. This is admitted by the whole human race [...] This poor meagre sordid language resembles nothing so much as the hissing of serpents or geese. [...] The distinction which English writers are too stupid to notice, but which the Irish Grammarians are perpetually talking of, the distinction between broad and narrow vowels—governs the English language. [...] If we follow the unwritten law of the English we shall pronounce (Celt) Selt but Cæsar would pronounce it, Kaylt. Thus the reader may take which pronunciation he pleases. He may follow the rule of the Latin or the rule of the English language, and in either case be right."
A guide to English pronunciation for Welsh speakers published in 1861 gives the alternative pronunciations "sel´tik, kel´tik" for the adjective Celtic.
The pronunciation with /s/ remained standard throughout the 19th to early 20th century, but the variant with /k/ seems to have gained ground during the later 20th century, especially among "students of Celtic culture". On the other hand, the /s/ pronunciation remains the most recognised form when it occurs in the names of sports teams, most notably Celtic Football Club and the Boston Celtics basketball team.
The corresponding words in French are pronounced with /s/, and English Celtic was formed in imitation of French celtique. The corresponding German terms are Kelten and keltisch, not only pronounced as /k/ but even spelled with ⟨k⟩. This is a regular German treatment of names in Greek kappa, also observed in cases such Cimbri, Cimmerians, Cambyses, etc. These spellings with ⟨k⟩ arise in the later 18th century. From the 16th to the early 18th century, the prevalent spelling in German was celtisch.
In current usage the terms "Celt" and "Celtic" can take several senses depending on context: The Celts of the European Iron Age, the group of Celtic-speaking peoples in historical linguistics, and the modern Celtic identity derived from the Romanticist Celtic Revival.
After its use by Edward Lhuyd in 1707, the use of the word "Celtic" as an umbrella term for the pre-Roman peoples of the British Isles gained considerable popularity. Lhuyd was the first to recognise that the Irish, British and Gaulish languages were related to one another, and the inclusion of the Insular Celts under the term "Celtic" from this time expresses this linguistic relationship. By the late 18th century, the Celtic languages were recognised as one branch within the larger Indo-European family.
The timeline of Celtic settlement in the British Isles is unclear and the object of much speculation, but it is clear that by the 1st century BC, most of Great Britain and Ireland was inhabited by Celtic-speaking peoples now known as the Insular Celts, divided into two large groups, Brythonic or P-Celtic, and Goidelic or Q-Celtic. The Brythonic groups under Roman rule were known in Latin as Britanni, while use of the names Celtae or Galli / Galatai was restricted to the Gauls. There are no specimens of Goidelic languages prior to the appearance of Primitive Irish inscriptions in the 4th century AD, however there are earlier references to the Iverni (in Ptolemy ca. 150, later also appearing as Hierni and Hiberni), and by 314, to the Scoti.
Simon James argues that, while the term "Celtic" expresses a valid linguistic connection, its use of both Insular and Continental Celtic culture is misleading, as archaeology does not suggest a unified Celtic culture during the Iron Age.[importance?][page needed]
With the rise of Celtic nationalism in the early to mid 19th century, the term "Celtic" also came to be a self-designation used by proponents of a modern Celtic identity. Thus, the contributor to "The Celt" discussing "the word Celt" states "The Greeks called us Keltoi", expressing a position of ethnic essentialism that extends the first person pronoun to include both 19th-century Irishmen and the Danubian Κελτοί of Herodotus.
This sense of "Celtic" is preserved in its political sense in Celtic nationalism of organisations such as the Celtic League, but it is also used in a more general unpolitical sense, in expressions such as Celtic music.
Latin Galli might be from an originally Celtic ethnic or tribal name, perhaps borrowed into Latin during the early 5th century BC Celtic expansions into Italy. Its root may be the Common Celtic *galno-, meaning "power" or "strength". The Greek Γαλάται Galatai (cf. Galatia in Anatolia) seems to be based on the same root, borrowed directly from the same hypothetical Celtic source which gave us Galli (the suffix -atai is simply an ethnic name indicator).
Schumacher's account is slightly different: He states that Galli (nominative singular *gallos) is derived from the present stem of the verb which he reconstructs for Proto-Celtic as *gal-nV- (it is not clear what the vowel in the suffix, marked as V, should be reconstructed as), whose meaning he gives as "to be able to, to gain control of", while Galatai comes from the same root and is to be reconstructed as nominative singular *galatis < *gelH-ti-s. He gives the same meaning for both reconstructs, namely "Machthaber", i. e. "potentate, ruler (or even warlord)", or alternatively "Plünderer, Räuber", i. e. "raider, looter, pillager, marauder", and points out that both names can be exonyms in order to explain their pejorative meaning. The Proto-Indo-European verbal root in question is reconstructed by Schumacher as *gelH-, whose meaning is given as "Macht bekommen über", i. e., "to acquire power over" in the Lexikon der indogermanischen Verben.
Gaul, Gaulish, Welsh
The English Gaul and French: Gaule, Gaulois are unrelated to Latin Gallia and Galli, despite superficial similarity. They are rather derived from the Germanic term walha, "foreigner, Romanized person", an exonym applied by Germanic speakers to Celts, likely via a Latinization of Frankish *Walholant "Gaul", literally "Land of the Foreigners/Romans", making it partially cognate with the names Wales and Wallachia), the usual word for the non-Germanic-speaking peoples (Celtic-speaking and Latin-speaking indiscriminately). The Germanic w is regularly rendered as gu / g in French (cf. guerre = war, garder = ward), and the diphthong au is the regular outcome of al before a following consonant (cf. cheval ~ chevaux). Gaule or Gaulle can hardly be derived from Latin Gallia, since g would become j before a (cf. gamba > jambe), and the diphthong au would be unexplained; the regular outcome of Latin Gallia is Jaille in French which is found in several western placenames.
The French term for "Welsh" is gallois, which is, however, not derived from the Latin Galli, but, like gaulois, borrowed (with suffix substitution) from Germanic *walhiska- "Celtic, Gallo-Roman, Romance" or its Old English descendant wælisc (= Modern English Welsh). The English form "Gaul" (first recorded in the 17th century) and "Gaulish" come from the French "Gaule" and "Gaulois", which translate Latin "Gallia" and "Gallus, -icus" respectively. In Old French, the words "gualeis", "galois", "walois" (Northern French phonetics keeping /w/) had different meanings: Welsh or the Langue d'oïl, etc. On the other hand, the word "Waulle" (Northern French phonetics keeping /w/) is recorded for the first time in the 13th century to translate the Latin word Gallia, while "gaulois" is recorded for the first time in the 15th century, and the scholars use it to translate the Latin words Gallus / Gallicus. The word comes from Proto-Germanic *Walha- (see Gaul: Name).
The English word "Welsh" originates from the word wælisċ, the Anglo-Saxon form of *walhiska-, the reconstructed Proto-Germanic word for "foreign" or "Celt" (South German Welsch(e) "Celtic speaker", "French speaker", "Italian speaker"; Old Norse "valskr", pl. "valir" "Gaulish", "French"), that is supposed to be derived of the name of the "Volcae", a Celtic tribe who lived first in the South of Germany and emigrated then to Gaul.
The Germanic term may ultimately have a Celtic source: It is possibly the result of a loan of the Celtic tribal name Volcae into pre-Germanic, *wolk- changing according to Grimm's Law to yield proto-Germanic *walh-. The Volcae were one of the Celtic peoples who for two centuries barred the southward expansion of the Germanic tribes (in what is now central Germany) on the line of the Harz mountains and into Saxony and Silesia.
In the Middle Ages, territories with primarily Romance-speaking populations, such as France and Italy, were known in German as Welschland as opposed to Deutschland, and the word is cognate with Vlach and Walloon as well as with the "-wall" in "Cornwall". Other examples are the surnames "Wallace" and "Walsh". During the early Germanic period, the term seems to have been applied to the peasant population of the Roman Empire, most of whom were in the areas immediately settled by the Germanic people.
The term Gael is, despite superficial similarity, also completely unrelated to Galli, see Gaels#Terminology.
The Celtic-speaking people of Great Britain were known as Brittanni or Brittones in Latin and as Βρίττωνες in Greek; an earlier form was Pritani, or Πρετ(τ)αν(ν)οί in Greek (as recorded by Pytheas in the 4th century BC, among others, and surviving in Welsh as Prydain, the old name for Britain). Related to this is *Priteni, the reconstructed self-designation of the people later known as Picts, which is recorded later in Old Irish as Cruithin and Welsh as Prydyn.
- H. D. Rankin, Celts and the classical world. Routledge, 1998 ISBN 0-415-15090-6. 1998. pp. 1–2. ISBN 978-0-415-15090-3. Retrieved 2010-06-07.
- Herodotus, The Histories, 2.33; 4.49.
- John T. Koch (ed.), Celtic Culture: a historical encyclopedia. 5 vols. 2006, p. 371. Santa Barbara, California: ABC-CLIO.
- P. De Bernardo Stempel 2008. Linguistically Celtic ethnonyms: towards a classification, in Celtic and Other Languages in Ancient Europe, J. L. García Alonso (ed.), 101-118. Ediciones Universidad Salamanca.
- Julius Caesar, Commentarii de Bello Gallico 1.1: "All Gaul is divided into three parts, one of which the Belgae live, another in which the Aquitani live, and the third are those who in their own tongue are called Celts (Celtae), in our language Gauls (Galli). Compare the tribal name of the Celtici.
- Parthenius, Love Stories 2, 30
- "Celtine, daughter of Bretannus, fell in love with Heracles and hid away his kine (the cattle of Geryon) refusing to give them back to him unless he would first content her. From Celtus the Celtic race derived their name." "(Ref.: Parth. 30.1-2)". Retrieved 5 December 2005.
- Lorrio, Alberto J.; Gonzalo Ruiz Zapatero (1 February 2005). "The Celts in Iberia: An Overview" (PDF). e-Keltoi 6: 183–185. Retrieved 5 October 2011.
- 'Celticos a Celtiberis ex Lusitania advenisse manifestum est sacris, lingua, oppidorum vocabulis', NH, II.13
- Celtici: Pomponius Mela and Pliny; Κελτικοί: Strabo
- 'Totam Celtici colunt, sed a Durio ad flexum Grovi, fluuntque per eos Avo, Celadus, Nebis, Minius et cui oblivionis cognomen est Limia. Flexus ipse Lambriacam urbem amplexus recipit fluvios Laeron et Ullam. Partem quae prominet Praesamarchi habitant, perque eos Tamaris et Sars flumina non longe orta decurrunt, Tamaris secundum Ebora portum, Sars iuxta turrem Augusti titulo memorabilem. Cetera super Tamarici Nerique incolunt in eo tractu ultimi. Hactenus enim ad occidentem versa litora pertinent. Deinde ad septentriones toto latere terra convertitur a Celtico promunturio ad Pyrenaeum usque. Perpetua eius ora, nisi ubi modici recessus ac parva promunturia sunt, ad Cantabros paene recta est. In ea primum Artabri sunt etiamnum Celticae gentis, deinde Astyres.', Pomponius Mela, Chorographia, III.7-9.
- Pomponius Mela, Chorographia, III.40.
- Eburia / Calveni f(ilia) / Celtica / Sup(ertamarca) |(castello?) / Lubri; Fusca Co/edi f(ilia) Celti/ca Superta(marca) / |(castello) Blaniobr/i; Apana Ambo/lli f(ilia) Celtica / Supertam(arca) / Maiobri; Clarinu/s Clari f(ilius) Celticus Su/pertama(ricus). Cf. Epigraphik-Datenbank Clauss / Slaby.
- [Do]quirus Doci f(ilius) / [Ce]lticoflavien(sis); Cassius Vegetus / Celti Flaviensis.
- Álvarez, Rosario, Francisco Dubert García, Xulio Sousa Fernández (ed.) (2006). Lingua e territorio (PDF). Santiago de Compostela: Consello da Cultura Galega. pp. 98–99. ISBN 84-96530-20-5.
- The Indians were wont to use no bridles, like the Græcians and Celts. Edward Topsell, The historie of foure-footed beastes (1607), p. 251 (cited after OED).
- (Lhuyd, p. 290) Lhuyd, E. "Archaeologia Britannica; An account of the languages, histories, and customs of the original inhabitants of Great Britain." (reprint ed.) Irish University Press, 1971. ISBN 0-7165-0031-0
- Laing, Lloyd and Jenifer (1992) Art of the Celts, London, Thames and Hudson ISBN 0-500-20256-7
- OED, s.v. "Celt", "Celtic".
- "Keltic". American Heritage Dictionary. Retrieved 21 November 2014.
- "Celtic or Keltic". Collins English Dictionary. HarperCollins. Retrieved 21 November 2014.
- "The word Celt", The Celt: A weekly periodical of Irish national literature edited by a committee of the Celtic Union, 28 November 1857: 287–288, retrieved 11 November 2010
- "Celtic", William Spurrell, An English-Welsh Pronouncing Dictionary, 1861: 45, retrieved 11 November 2010
- "Although many dictionaries, including the OED, prefer the soft c pronunciation, most students of Celtic culture prefer the hard c." MacKillop, J. (1998) Dictionary of Celtic Mythology. New York: Oxford University Press ISBN 0-19-869157-2
- but not Latin names such as Cicero, Cato; Kaiser is a special case as it is not a learned introduction into Modern German but a loan inherited from Old High German.
- An early attestation is found in volume 2 of Sebastian Franck's and Nikolaus Höniger's Chronick of 1585 
- (Lhuyd, p. 290) Lhuyd, E. (1971) Archaeologia Britannica; An account of the languages, histories, and customs of the original inhabitants of Great Britain. (reprint ed.) Irish University Press, ISBN 0-7165-0031-0
- Schumacher, Stefan; Schulze-Thulin, Britta; aan de Wiel, Caroline (2004). Die keltischen Primärverben. Ein vergleichendes, etymologisches und morphologisches Lexikon (in German). Innsbruck: Institut für Sprachen und Kulturen der Universität Innsbruck. pp. 325–326. ISBN 3-85124-692-6.
- Rix, Helmut; Kümmel, Martin; Zehnder, Thomas; Lipp, Reiner; Schirmer, Brigitte (2001). Lexikon der indogermanischen Verben. Die Wurzeln und ihre Primärstammbildungen (in German) (2nd, expanded and corrected ed.). Wiesbaden, Germany: Ludwig Reichert Verlag. p. 185. ISBN 3-89500-219-4.
- Sjögren, Albert, "Le nom de "Gaule", in "Studia Neophilologica", Vol. 11 (1938/39) pp. 210-214.
- Oxford Dictionary of English Etymology (OUP 1966), p. 391.
- Nouveau dictionnaire étymologique et historique (Larousse 1990), p. 336.
- Neilson, William A. (ed.) (1957). Webster's New International Dictionary of the English Language, second edition. G & C Merriam Co. p. 2903.
- Koch, John Thomas (2006). Celtic culture: a historical encyclopedia. ABC-CLIO. p. 532. ISBN 1-85109-440-7.
- Mountain, Harry (1998). The Celtic Encyclopedia, Volume 1. uPublish.com. p. 252. ISBN 1-58112-889-4.