EntityQ1141109· pop 16· linked from 222 articlesRoom 40Sign in to savecryptanalysis departmentConnectionsWorld War IConceptZimmermann telegramEntityForeign, Commonwealth and Development OfficeEntityGovernment Communications HeadquartersEntityMaritz RebellionEntitySenussi campaignEntityDefence IntelligenceEntitylist of intelligence agencies of the United KingdomEntityMI1EntityUnited StatesCountryMexicoCountryEstoniaCountryBerlinEntityWinston ChurchillPersonNorth SeaEntityBritish EmpireEntityInternational Standard Book NumberEntityTreaty of VersaillesEntityEnglish ChannelEntityRussian RevolutionEntityCategories1914 establishments in the United Kingdom1919 disestablishments in the United KingdomCryptography organizationsGovernment agencies established in 1914History of cryptographyIndividual roomsLocations in the history of espionageMilitary history of the United Kingdom during World War IMilitary units and formations of the Royal Navy in World War IRoyal Navy shore establishmentsSignals intelligence of World War I