Title: "Blinker" Hall, spymaster
Subjects: World War (1914-1918) fast (OCoLC)fst01180746, World War, 1914-1918, Cryptography, Great Britain. Royal Navy, Secret service, Great Britain. Naval Intelligence Division, Admirals, Great Britain, Biography, Great britain, royal navy, history, World war, 1914-1918, great britain, Great britain, biography, Intelligence specialists, History