Names and terminology
, 2nd century: "APANA·AMBO(-) /
(castello) MAIOBRI /
The first recorded use of the name of Celts – as Κελτοί (Keltoi) – 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 fifth 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 *kʲel 'to hide' (present also in Old Irish ceilid), IE *kʲel '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".
In the 1st century BC, Julius Caesar reported that the people known to the Romans as Gauls (Latin: Galli) called themselves Celts, which suggests that even if the name Keltoi was bestowed by the Greeks, it had been adopted to some extent as a collective name by the tribes of Gaul. The geographer Strabo, writing about Gaul towards the end of the first century BC, refers to the "race which is now called both Gallic and Galatic," though he also uses the term Celtica as a synonym for Gaul, which is separated from Iberia by the Pyrenees. Yet he reports Celtic peoples in Iberia, and also uses the ethnic names Celtiberi and Celtici for peoples there, as distinct from Lusitani and Iberi. Pliny the Elder cited the use of Celtici in Lusitania as a tribal surname, which epigraphic findings have confirmed.
Latin Gallus (pl. Galli) might stem from a Celtic ethnic or tribal name originally, perhaps one borrowed into Latin during the Celtic expansions into Italy during the early fifth century BC. Its root may be the Proto-Celtic *galno, meaning "power, strength", hence Old Irish gal "boldness, ferocity" and Welsh gallu "to be able, power". The tribal names of Gallaeci and the Greek Γαλάται (Galatai, Latinized Galatae; see the region Galatia in Anatolia) most probably have the same origin. The suffix -atai might be an Ancient Greek inflection. Classical writers did not apply the terms Κελτοί (Keltoi) or Celtae to the inhabitants of Britain or Ireland, which has led to some scholars preferring not to use the term for the Iron Age inhabitants of those islands.
Celt is a modern English word, first attested in 1707, in the writing of Edward Lhuyd, whose work, along with that of other late 17th-century scholars, brought academic attention to the languages and history of the early Celtic inhabitants of Great Britain. The English form Gaul (first recorded in the 17th century) and Gaulish come from the French Gaule and Gaulois, a borrowing from Frankish *Walholant, "Land of foreigners or Romans" (see Gaul: Name), the root of which is Proto-Germanic *walha-, "foreigner, Roman, Celt", whence the English word Welsh (Old English wælisċ < *walhiska-), South German welsch, meaning "Celtic speaker", "French speaker" or "Italian speaker" in different contexts, and Old Norse valskr, pl. valir, "Gaulish, French"). Proto-Germanic *walha is derived ultimately from the name of the Volcae, a Celtic tribe who lived first in the south of Germany and in central Europe and then migrated to Gaul. This means that English Gaul, despite its superficial similarity, is not actually derived from Latin Gallia (which should have produced **Jaille in French), though it does refer to the same ancient region.
Celtic refers to a family of languages and, more generally, means "of the Celts" or "in the style of the Celts". Several archaeological cultures are considered Celtic in nature, based on unique sets of artefacts. The link between language and artefact is aided by the presence of inscriptions. The relatively modern idea of an identifiable Celtic cultural identity or "Celticity" generally focuses on similarities among languages, works of art, and classical texts, and sometimes also among material artefacts, social organisation, homeland and mythology. Earlier theories held that these similarities suggest a common racial origin for the various Celtic peoples, but more recent theories hold that they reflect a common cultural and language heritage more than a genetic one. Celtic cultures seem to have been widely diverse, with the use of a Celtic language being the main thing they had in common.
Today, the term Celtic generally refers to the languages and respective cultures of Ireland, Scotland, Wales, Cornwall, the Isle of Man, and Brittany, also known as the Celtic nations. These are the regions where four Celtic languages are still spoken to some extent as mother tongues. The four are Irish Gaelic, Scottish Gaelic, Welsh, and Breton; plus two recent revivals, Cornish (one of the Brittonic languages) and Manx (one of the Goidelic languages). There are also attempts to reconstruct Cumbric, a Brittonic language from North West England and South West Scotland. Celtic regions of Continental Europe are those whose residents claim a Celtic heritage, but where no Celtic language has survived; these areas include the western Iberian Peninsula, i.e. Portugal and north-central Spain (Galicia, Asturias, Cantabria, Castile and León, Extremadura).
Continental Celts are the Celtic-speaking people of mainland Europe and Insular Celts are the Celtic-speaking peoples of the British and Irish islands and their descendants. The Celts of Brittany derive their language from migrating insular Celts, mainly from Wales and Cornwall, and so are grouped accordingly.