The conventional assumption that the pre-Roman populations of Britain and Ireland were ethnically Celtic, and that Celtic culture survived in the north and west beyond the Roman occupation of Britain, was first challenged in the 1990s in a critical process that has sometimes since been parodied beyond the legitimate questions raised by Celtosceptics. Whilst it is true that the term ‘Celtic’ was only widely applied to speakers of a language group from the eighteenth century, the equation of linguistically Celtic speaking Gauls with Celts of ancient historians still seems archaeologically and linguistically tenable, even if the case for equating Celtic-speaking Britons with ethnic Celts is no more than inference. By the same rationale, Celtic art should refer to the art of people who might reasonably be regarded as ethnic Celts (including those who regarded themselves as Celtiberians), and not just to La Tène art, which is both chronologically and geographically restricted. The case for regarding early Irish Christian art as Celtic is largely specious, except as a product of the ‘Celtic’ church. The case for regarding the origins of the Celts as extending back into earlier prehistory carries conviction, though the further suggestion that these origins lay in South-Western Europe remains far from persuasive to many linguists as well as to archaeologists.