The so‐called ‘traditional’ costumes of Wales and the Highlands of Scotland are not as ancient as is often claimed. They are the joint invention of romantics and commercial interests in the early 19th century. Tourists and artists who visited Wales in the late 18th century did not note a national dress, though they did observe that women in the mountains often wore large blue or red tweed cloaks and tall black hats of the type that had gone out of fashion in lowland England in the first half of the 17th century. These had survived in remote parts of Wales simply through conservatism. The cloak and tall hat were deliberately turned into a national costume for women in the 1830s by the leaders of the picturesque romantic Welsh revival. See Prys Morgan, ‘From Death to a View: The Hunt for the Welsh Past in the Romantic Period’, in Eric Hobsbawm and Terence Ranger (eds), The Invention of Tradition (1983). In the same volume, see Hugh Trevor‐Roper, ‘The Invention of Tradition: The Highland Tradition of Scotland’, which shows that the kilt was designed by a Lancashire Quaker, Thomas Rawlinson, in the late 1720s for the Highlanders who worked at his furnace near Inverness. The kilt was an improved version of the belted plaid that had been used previously by the poorer Highlanders, though some preferred trews. At this time, clans did not wear distinctive tartans. The idea that a certain design of tartan identified a particular group originated with the Highland regiments that were formed after the defeat of the 1745–6 rebellion. A romanticized picture of the Highlanders was gradually created by writers, notably Sir Walter Scott and Colonel David Stewart, the author of Sketches of the Character, Manners and Present State of the Highlanders of Scotland (1822). The publicity given to George IV's visit to Edinburgh in 1822, when he was portrayed wearing a kilt, had an enormous impact. Local businesses seized the opportunity to invent distinctive clan tartans for the occasion and to create the full Highland dress that is now regarded as traditional.
A suitable analogy is provided by the costume of Brittany. Old theories about the ancient origins of the distinctive dress that is worn on special occasions have been shown to be wrong. Instead, R. Y. Creston, Le Costume Breton (1974), has established beyond doubt that Breton costume, like other regional styles of dress in France, originated in fashions that were disseminated from Paris and the court, from the 17th century onwards, but particularly after the Revolution of 1789. A few older influences can be discerned, but Brittany did not possess a distinctive local costume before the Revolution. The elaborate costumes worn now at festivals were unknown; feminine costumes were completely plain and strictly utilitarian. After the Revolution peasants all over France adopted costumes imitating those of the ruling classes. Only gradually did regional styles develop from these. See Costume, the annual journal of the Costume Society (founded 1965).