Based on the ancient Welsh gods of Don, the teachings evolved into a oral Faerie Tradition. The Children of Don chose to stay in Wales after the invasion of the Celts, and took refuge under the hills.  Faerie Folk of Wales or Y Dynion Mwyn are man sized Faeries, and supposedly the spirits of Pict heros. They live underground, in Dolmens or underwater. Of these we can derive the Heroic Faerie and the Medieval Fairie. Wales has two races, a visible race called the Cymry and the invisible Faerie People or the Dynion Mwyn.