She published her first volume in 1936 under the publisher's title of "The Virgin and the Swine". Although receiving warm praise from John Cowper Powys, the book sold poorly and none of the other novels in the series reached print at the time. Rediscovered by Ballantine's Adult Fantasy series in 1970, it was reissued as "The Island of the Mighty". "The Children of Llyr" followed in 1971, "The Song of Rhiannon" in 1972 and "Prince of Annwn" in 1974. All four novels were published in a single volume as "The Mabinogion Tetralogy" in 2002 by Overlook Press. The four novels are translated and available in several European languages.