walhaz > walh > wealh > Wēalas > Wales
walhaz > walh > wealh > (+Körnɨw) Wēalas > Cornwall
walhaz > walh > Wallon > Walloon > Wallonia
walhaz > walhs > valxu > volxъ > volox > Walache > valah > Valahia > Wallachia
Words For Granted has an episode about Wales and its etymology. Tldr: It goes back to Proto Germanic and meant “foreign” (originally for Romance languages, later everything they didn’t understand). Hence also the German “Kauderwelsch” which basically means unintelligible gibberish
It goes deeper: the word was originally for a Celtic tribe, the Volcae. Then Celts in general. Then Latin/Romance speakers (since the Celts were being assimilated), and then foreigners. Borrowing probably happened around the first millennium BCE since it underwent /k/→/h/ (Grimm’s Law), so it’s really old.
So that’s where walnuts are from! (yup, same etymology: *walhaz + *hnuts)
