The held at Churchill Archives Centre chiefly consist of the papers and letters Montgomery Hyde collected and generated in the course of writing three of his books: "The Quiet Canadian" (a biography of Sir William Stephenson, Director of British Security Co-ordination in the Western Hemisphere, 1940-46); "Cynthia" (a biography of the British agent Elizabeth (Pack) Brousse); and "Secret Intelligence Agent" (which included descriptions of his own wartime experiences). The collection also includes papers and letters relating to Hyde's work in Censorship and Security in Gibraltar, Bermuda and the USA during the Second World War; and in the legal division of the Allied Control Commission in Austria.