Following Freud's death in 1939, the radical theories of Melanie Klein were the subject of prolonged controversy and fierce debate within the British Psycho-Analytical Society. At the time, individuals fought passionately in support of their positions. In the midst of, or as a result of, the personal animosities and political manoeverings, important intellectual contributions were made, and practical decisions taken, which were to affect the development of psychoanalysis down to the present day. The Freud-Klein Controversies 1941-45 offers the first complete record of the debate, including all relevant papers and correspondence, based on previously closed archive material which is presented without censorship.