German code book 13040, used for encoding Zimmerman message

Date: 1916-1917 Reference: HW 3/176 (11v) Creator: Records created or inherited by Government Communications Headquarters (GCHQ) Catalogue context: German code book 13040, used inter alia for encoding Zimmerman message. Transferred from HW 7/9 in August 1995 Categories: First World War; Overseas Subjects: Communications; Intelligence; International; Personal and family papers Topics: Arts and culture; Family and identity; International trade and affairs; Military and war Period: Early 20th Century Places: Germany Copyright information: Copyright clearance for publication is not required, except in the case of documents in third-party copyright. Usage terms: https://www.nationalarchives.gov.uk/documents/information-management/use-of-tna-materials.pdf