With this work Lt. Col. Thomas G. Fergusson (USA) becomes the first author to publish in English a detailed and scholarly history of a modern military intelligence establishment, in this case, Britain's department for both strategic and tactical military intelligence from 1879 to 1914. Colonel Fergusson skillfully narrates how the Intelligence Department at the War Office was formed and how it progressed. He traces its revival under Henry Brackenbury, its role in the South African War, and the development of a field intelligence system on the eve of World War I. He shows how the size, structural methods and relative importance of that intelligence department changed in the decades between the Franco-Prussian War and World War I. Finally, he evaluates the readiness of the Intelligence Department for the war.