The King of Britain's Daughter has been specially commissioned as the text of an oratorio for the 1993 Hay on Wye Festival, and is based on the story in the Mabinogion of Branwen, the daughter of Llyr. Family legend associated the story with Fforest, the family farm, where the giant's footprint is preserved as a rock pool, and Fforest and Welsh legend have provided the inspiration for this part of the book, which also contains a variety of other vivid and memorable poems.