H. D. (Hilda Doolittle) was one of the central figures in literary modernism in the 1910s. She collaborated with Ezra Pound and others and played an important role in the early development of modernist poetry. This Cambridge Companion is a critical introduction to H. D. containing essays on all her major works. The first part explores the author's initial exclusion from the canon and her subsequent reinstatement; her tendency to merge fact with fiction in her autobiographical texts; her contribution to the little magazines; her relation to modernism; her representation of gender; and her influence on later generations of writers. The second part offers close and accessible critical analyses of H. D.'s style, her poems Hymen and Trilogy, her novels HERmione and Majic Ring, her understanding of translation as literary practice and of her notion of history in Tribute to Freud and The Gift.