Brythonic conlang

[smmg]

I think figuring out where to put my conlang is the most important first step? Because it's location is going to effect what languages it's near/been influenced by/etc. I'm thinking I'll put it somewhere in the Old North (à la Cumbric or Pictish), or I'm making a new island and sticking it somewhere in the Atlantic or the North Sea or perhaps between Britain and Ireland (à la the Island of Sodor from Thomas the Tank Engine). Or perhaps stick it somewhere on the continent, but still be an insular Celtic language not a continental one (à la Breton)