Lite Linguistics is a TikTok channel focused on world languages. They recently produced a video on Breton language.
This is how they explained it.
"Hello welcome to lite linguistics
Meet Breton a Celtic language spoken in the Brittany region of Northwestern France
Around 275 BCE there were Celtic languages all over Europe, spanning all the way from Iberia to Anatolia but as the Latin speaking Romans and the various Germanic tribes came in they pushed these Celtic peoples out.
Which leaves us with just these modern day darker green Celtic languages.
Now Breton is the only Celtic language remaining on the European mainland but even then it was brought over by Celtic speakers from Great Britain around the year 800 AD.
So it's more closely related to Welsh and Cornish than it is to any extinct Celtic continental language the government of France has tried to put it down many many times throughout the centuries.
Breton has no status at the national level.
Breton is the only Celtic language that has no recognition in their national government but despite all the opposition people keep speaking it and keep learning it."
is an organization established to create, facilitate, promote, and sponsor wide-ranging innovative and collaborative cultural and economic projects that strengthen and foster relations and cooperation between the United States of America and the region of Brittany, France.