Pan-Celticism is the name given to various political and cultural movements and organisations that promote greater contact between the Celtic nations, as defined by these organizations.
There is some controversy surrounding the term Celts. One such example was the Celtic League's Galician crisis. This was a debate over whether the Spanish region of Galicia should be admitted. The application was rejected on the basis of language.
Some Austrians claim that they have a Celtic heritage that became Romanized under Roman rule and later Germanized after Germanic invasions. Austria is the location of the first characteristically Celtic culture to exist. After the annexation of Austria by Nazi Germany in 1938, in October 1940 a writer from the Irish Press interviewed Austrian physicist Erwin Schrödinger who spoke of Celtic heritage of Austrians, saying "I believe there is a deeper connection between us Austrians and the Celts. Names of places in the Austrian Alps are said to be of Celtic origin." Contemporary Austrians express pride in having Celtic heritage and Austria possesses one of the largest collections of Celtic artefacts in Europe
Organisations such as the Celtic Congress and the Celtic League use the definition that a 'Celtic nation' is a nation with recent history of a traditional Celtic language.
Pan-Celticism can operate on one or all of the following levels listed below:
Linguistic organisations promote linguistic ties, notably the Gorsedd in Wales, Cornwall and Brittany, and the Irish government-sponsored Columba Initiative between Ireland and Scotland. Often, there is a split here between the Irish, Scots and Manx, who use Q-Celtic Goidelic languages, and the Welsh, Cornish and Bretons, who speak P-Celtic Brythonic languages.