This article considers Bion’s writings about World War I, from the returning soldier of 1919 to the psychoanalyst in his seventies. It asks how and why his memories of the war shifted over time, and explores the connections between his experiences as a tank commander in the war and his clinical work forty years later. Bion’s psychoanalytic thought shared much with British contemporaries such as Donald Winnicott and John Bowlby in putting early domestic relationships and the maternal relation at the center, but it also bore traces of his war. On the Western Front during 1917-18 Bion was exposed to the kinds of psychotic states he would later observe in his patients. At the same time, concepts such as containing, bizarre objects and reverie gave Bion a psychoanalytic idiom for remembering the war in later life. Psychoanalysis, however, was not the only influence. A secure home life from the 1950s also made it possible for him to bring the war to mind. The professional discoveries of the psychoanalyst after World War II were closely linked to the emotional experiences of the World War I veteran and husband.