In 1916 William Butler Yeats, Edmund Dulac, and Ezra Pound were caught up together in the study of Japanese Noh drama, and were experimenting with a production of Yeats' first play using that form, "At the Hawk's Well." This collection of Yeatsfs correspondence with Dulac, which begins in that year, extends through 1938, and takes up all the major concerns of Yeats’s supremely creative later years: occultism, painting, theater, stamp and coin design, Eastern philosophy, and the two great preoccupations of his late poetry: his cyclical theory of history, set forth in A Vision, and his concept of the proper music for sung poetry. Yeats wrote to Dulac as his closest male friend, and their correspondence covers the crucial events of the poet’s later life: his marriage, the American tour, the reconstruction of Thoor Ballylee, the Nobel Prize, Lady Gregory’s death, the Civil War, Maud Gonne’s internment and escape to Ireland, the births of Yeats’s children, his appointment as Senator, his seventieth birthday celebration, his collaboration with Shri Purohit Swami, his infatuation with Margot Collis, the BBC broadcasts of his poetry, and his final illness. Of these 116 letters, only eight are published in Allan Wade’s The Letters of W. B. Yeats, two of them in much abridged form. I include in the notes to the letters several articles which are not, to my knowledge, published in full elsewhere: a 1922 version of the Introduction to the 1925 A Vision, Cecil Salkeld’s memoir of the composition of the "Centaur" poem, Yeats’s account of the incident with Margot Collis at Barcelona, Dulac’s essay, Music and Poetry, his lecture on symbolism, and his account of the visit he and Yeats paid to the occultist, David Calder Wilson. Other letters in the collection which bear on the subjects of Yeats1s correspondence with Dulac are quoted in the notes, including Lily Yeats’s to Dulac concerning the design for the centaur bedspread, Yeats’s to William Maxwell explaining the symbols used in the illustrations for his books, and Margot Collis’s to Dulac. I have divided the letters into eight groups. The first is primarily concerned with the production of the Noh play, the second with occultism, the third with three major design projects which Yeats commissioned from Dulac, and the fourth with the Civil War and the composition of the "Centaur" poem. The fifth is centered around the 1922 Vision Introduction, the sixth covers affairs of state, the seventh the composition of "A Full Moon in March," and a proposed London season of Yeats’s plays, and the last, the broadcasts of his poetry and the ensuing row over the proper music for sung poetry.