This is the first of two projected volumes on the history of operational research (OR) in Britain commissioned by the UK Operational Research Society. Based upon a vast array of published and unpublished sources, the book provides an original account of the discipline's pre-war and wartime origins. This serves as a prelude to a wide-ranging analysis of the diffusion of OR into the public and private sectors after 1945. The chapters on the role of OR in iron and steel and coal-mining, and its rapid adoption in the UK corporate sector after 1960, should be of particular interest to practitioners. The book also analyses and explains the diffusion of OR into local and central government and provides an informed commentary on the origins and subsequent history of the OR Society. Professor Kirby has related the development of OR in the UK to contemporary developments in the USA. The book concludes with a resume of the post-1970 debates concerning the future trajectory of OR.