Cathleen ni Houlihan is a one-act play written by William Butler Yeats and Lady Gregory in 1902. It was first performed on 2 April of that year and first published in the October number of Samhain. Lady Gregory wrote the naturalistic peasant dialogue of the Gillane family, while Yeats wrote Cathleen Ni Houlihan's dialogue. Yeats later expressed reservations about the play's nationalistic rhetoric of blood sacrifice, asking in a later poem, "The Man and the Echo," "Did that play of mine send out / Certain men the English shot?"