Denis Devlin died on August 21, 1959. The collection The Heavenly Foreigner was published posthumously.
Further Reading
Wilson, James Matthew. "Late Modernism and the Marketplace in Denis Devlin's The Heavenly Foreigner." Irish Modernism: Origins, Contexts, Publics. Eds. Edwina Keown and Carol Taaffe. Reimagining Ireland 14. Bern: Peter Lang, 2010. 159-175.