John Bowlby's theory of attachment is examined in the cultural and historical context in which it was developed. Bowlby trained as a psychiatrist in England during the 1920's and published the WHO report in 1951. Thus the origins of his theory can be related to events set in motion by the First World War and occurring during the interwar period and the Second World War. Bereavement was a widespread problem during and after the war, often precipitating cases of shell shock and civilian illness. Treatment of these problems led to widespread recognition in British psychiatry of the importance of neurotic as well as psychotic illness, of the role of environmental events in etiology, and of the importance of considering patients' relationship to other people as well as their individual psychology. It was recognized that infantile sexual trauma was not a necessary prerequisite to neurosis and infantile interaction with the mother was identified as another possible source of trauma. Another theory demoted the importance of sexual instinct and postulated an innate need for companionship whose frustration led to anger or depression. The culmination of these changes set the stage for Bowlby's work, which began in the late fifties and involved a conscious use of adult mourning as a paradigm for childhood separation anxiety. Implications relating to the generalizability of Bowlby's theory are discussed. (JMB)