Ar Priñs Bihan, in Breton (Brezhoneg).
Breton is a Celtic language spoken in Brittany (Bretagne). It is also the last and only Celtic language in use on the European mainland. Bretagne should remind you to Astérix the Gaul. But for me, it reminds me to my first journey overseas. Paris is the first city I visited, but then I spent one week in Bretagne: Lannion, Perros-Guirec, Pleumeur-Bodou, Guingamp, etc.
Breton was brought from Great Britain to Armorica (the ancient name for the coastal region that includes the Brittany peninsula) by migrating Britons during the Early Middle Ages, making it an Insular Celtic language. Breton is most closely related to Cornish, another Southwestern Brittonic language. Welsh and the extinct Cumbric, both Western Brittonic languages, are more distantly related.
Having declined from more than 1 million speakers around 1950 to about 200,000 in the first decade of the 21st century, Breton is classified as “severely endangered” by the UNESCO Atlas of the World’s Languages in Danger.