A modern Celtic identity emerged in Western Europe following the identification of the native peoples of the Atlantic fringe as Celts by Edward Lhuyd in the 18th century. Lhuyd and others equated the Celts described by Greco-Roman writers with the pre-Roman peoples of France, Great Britain and Ireland. The Irish and ancient British languages were thus Celtic languages. The descendants of these languages were the Brittonic (Breton, Cornish and Welsh variants) and Gaelic (Irish, Manx and Scottish variants) languages. These peoples were therefore modern Celts. Attempts were made to link their distinctive cultures to those of the Ancient Celtic people.
The concept of modern Celtic identity evolved during the course of the 19th-century into the Celtic Revival. By the late 19th century, it often took the form of ethnic nationalism, particularly within the United Kingdom of Great Britain and Ireland, where the Irish Home Rule Movement resulted in the secession of the Irish Free State, in 1922. There were also significant Welsh, Scottish and Breton nationalist movements, giving rise to the concept of Celtic nations. After World War II, the focus of the Celtic movement shifted to linguistic revival and protectionism, e.g. with the foundation of the Celtic League in 1961, dedicated to preserving the surviving Celtic languages.