Brithenig

Brithenig, or also known as Comroig, is an invented language, or constructed language ("conlang"). It was created as a hobby in 1996 by Andrew Smith from New Zealand, who also invented the alternate history of Ill Bethisad to "explain" it. Officially according to the Ill Bethisad Wiki, Brithenig is classified as a Britanno-Romance language, along with other Romance languages that displaced Celtic.

Brithenig was not developed to be used in the real world, like Volapük, Esperanto, Interlingua or Interslavic, or to provide detail to a work of fiction, like Klingon from the Star Trek franchise. Rather, Brithenig started as a thought experiment to create a Romance language that might have evolved if Latin had displaced the native Celtic language as the spoken language of the people in Great Britain.