From the 5th cent. bc, Greek ethnographers described the Celts as one of the major ethnic groups of central and western Europe, locating them inland from Marseilles. Caesar in De bello Gallico states that only the Gauls of central and southern Gaul called themselves Celts, with Belgae living in the north of Gaul and Aquitani in the south‐west.
Interest revived in the Celts during the Renaissance. In 1582 George Buchanan claimed that the former inhabitants of Britain were Celts or Gauls on the basis of similarity in ancient place‐names in Gaul and Britain. The term ‘Celt’ was thus extended to refer to speakers of these languages—Bretons, Celts, Cornish, Welsh, Irish, Manx, and Scottish.
To identify the ancient Celts, 18th‐ and 19th‐cent. scholars turned to archaeology, describing certain objects and burial rites as ‘Celtic’. Kemble and Franks, as early as 1863, had referred to objects from Britain decorated in a distinctive curvilinear art style as ‘Celtic’. This art style was also found on the objects fished out at La Tène on Lake Neuchâtel in Switzerland. By the late 19th cent. the La Tène culture became that of the Celtic peoples, and La Tène art became ‘Celtic’ art. It was also assumed that there was a close correlation between ethnicity, language, art, and material culture. Scholars such as Powell (1958) and Filip (1962) used archaeology to seek the origin and spread of the La Tène culture. On the evidence of the continuity of burial rites from the preceding Hallstatt period, and of a concentration of richly decorated early La Tène art objects, the centre of origin was identified as northern France–western Germany, more specifically in Champagne. From these areas it was claimed the Celts expanded in the 4th and 3rd cents. bc by migrating into southern and western France, Britain, and central Europe.
This explanation has come under increasing criticism. It does not account for Celtic‐speaking groups in Iberia where La Tène objects are rare; the supposed invasion of Britain in the 4th–3rd cents. bc corresponds with the period when insular–continental contacts were at their lowest; and continuity from the early to the late Iron Age is seen as the norm in virtually all areas where the archaeological record is sufficiently complete (e.g. Britain). The supposed ‘expansion’ of the Celts is largely a product of misinterpretation of the archaeological record. This revised, and still disputed, view of the Celts is forcing us to adopt new models for the diffusion and adoption of language, material culture, and art styles, independent of one another. The naming of the language group as ‘Celtic’ is seen as an arbitrary choice by 17th‐cent. scholars—it could have equally been Britannic, Belgic, or Gallic. If we accept that there were never any Celts in antiquity in Britain, it follows that terms such as the ‘Celtic’ church, Celtic art, or indeed the description of the Welsh, Irish, and Scots as ‘Celts’ are without historical foundations.