In Wales it was a dance tune; so far as I know, it never had any Welsh language text. It's unlikely ever to have had a Gaelic text, either, though there was a Scottish song sung to a form of the tune. It first appeared, as The Red House, in Playford's Dancing Master (1695, not 1706 as I stated in the mammoth John Peel thread), and may originally have been English. All this information in greater detail in the thread I linked to (along with some bizarre misunderstandings as to the identity of Mr. Peel).