The author throws a new light on a neglected aspect of W.R. Bion's life and work, i.e. his relationship to his first analyst, John Rickman, by making reference not only to the latter's career and scientific work, but also to the 27 letters which Bion wrote to him in the years 1939–1951 that he found in the Archives of the British Psychoanalytical Society. As the letters show, in the close collaboration they developed during the Second World War as army psychiatrists, we can find not only the origins of the new concept of “therapeutic community” and of Bion's later book Experiences in groups, but also see how crucial their unique relationship was to the realization of such important goals.