Room 47: The Persian Prelude to the Zimmermann Telegram

During the First World War, Persia was the scene of early British cryptanalytical successes against German diplomatic codes and ciphers under the auspices of Room 47 (one of the suite of rooms which for convenience have been listed under “Room 40 OB” or the Old Building of the British Admiralty in London). It is the contention of this article, based on newly discovered archival material, that there is a strong, and previously undetected link with the Zimmermann Telegram, which David Kahn has called “the greatest intelligence coup of all time.”