Did not Bryn Terfel a couple of years or so ago sing a few verses of 'Rule Britannia' in Welsh at the Last Night of the Proms? I seem to recall that he was dressed in a Welsh rugby shirt, and held a rugby ball in his hand while he sang, and which he then tossed into the auditorium. Made me cringe. Other than those verses, probably cobbled together for the occasion, I doubt very much if a Welsh version exists. I have come across a 19th century obsequious translation of 'God Save the Queen', which should go down like a lead balloon at a Celtic evening. Tegwyn