The Mabinogion Tetralogy

Series of fantasy novels by Evangeline Walton 1. The Virgin and the Swine (November 1936; Republished as The Island of the Mighty in July 1970) 2. The Children of Llyr (August 1971) 3. The Song of Rhiannon (August 1972) 4. Prince of Annwn (November 1974)