The medieval Welsh bardic grammars were composed and transmitted during a period of intense social and political change in Wales. These documents, which contain both a highly Latinate description of the Welsh language and a treatment of the strict poetic metres, began their life as essentially vernacular artes poetriae. However, from the early fourteenth century to the end of the sixteenth, they were recopied and revised over and over by bards, bureaucrats, antiquarians, humanists, and the...