The Breton word 'gwezboell' is the equivalent of the Welsh 'gwyddbwyll' and the Irish 'fidchell'. These last two words often feature in ancient Welsh and Irish legends, referring to a board game. What exactly that board game was is unclear; it may have been a Celtic version of hnefatafl, it may have been a Celtic version of the Roman game ludus latrunculorum, it may have been something entirely different. Or it may have been all of the above, at different times; more on that in a future blog post.
I don't remember where I got this commercial Gwezboell set; it was many years ago. Although the box proclaims gwezboell to be 'Celtic chess', the creators of this set clearly adhered to gwezboell being a version of hnefatafl. A 9 x 9 version to be precise, with the king escaping at the board's corners.
The board itself is made from cardboard, and the pieces are plastic chess pieces: a king plus 8 + 16 pawns. All in all a very basic set.
By the way, the picture is the only thing I still have of this set; I can't find it anywhere ...