"Arpitania" roughly corresponds to the historical County of Savoy and its successor state the Duchy of Savoy: The terms Arpitan and Arpitania (Arpitanie) are neologisms coined in the 1970s by Joseph Henriet (born 1945), a Communist school teacher who was influenced by the Basque activist Federico Krutwig.
In his Garaldea (published 1978), Krutwig names the Basques "Garalditans", a purported Neolithic race which he claimed existed thousands of years ago.
Looking for racial or linguistic remnants of the "Garalditans", he moved to the Aosta Valley in 1970, constructing Basque etymologies for local placenames.
Pichard (2009) suggests its newfound success was due to the happy rhyme with Occitan and the unwieldiness of the alternative francoprovençal.
The alternative term patois, while viewed with affection in Switzerland, has a condescending or "humiliating" connotation in France.