19 Facts About MI5


Security Service, known as MI5, is the United Kingdom's domestic counter-intelligence and security agency and is part of its intelligence machinery alongside the Secret Intelligence Service, Government Communications Headquarters, and Defence Intelligence .

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MI5 is directed by the Joint Intelligence Committee, and the service is bound by the Security Service Act 1989.

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Service marked its centenary in 2009 by publishing an official history titled The Defence of the Realm: The Authorised History of MI5, written by Christopher Andrew, Professor of Modern and Contemporary History at Cambridge University.

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MI5 proved consistently successful throughout the rest of the 1910s and 1920s in its core counter-espionage role.

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MI5 used a method that depended on strict control of entry and exit to the country and, crucially, large-scale inspection of mail.

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MI5's expertise, combined with the early incompetence of the Soviets, meant the bureau was successful in correctly identifying and closely monitoring these activities.

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MI5 therefore undertook no tangible intelligence operations of consequence during the Irish War of Independence.

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MI5 did undertake the training of British Army case-officers from the Department of Military Intelligence, for the Army's so-called "Silent Section", otherwise known as M04.

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MI5 operated in Italy during inter-war period, and helped Benito Mussolini get his start in politics with a £100 weekly wage.

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Agents who agreed to this were supervised by MI5 in transmitting bogus 'intelligence' back to the German secret service, the Abwehr.

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MI5's role was to be available to be consulted by any member or former member of the security and intelligence services who had "anxieties relating to the work of his or her service" that it had not been possible to allay through the ordinary processes of management-staff relations, including proposals for publications.

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MI5 is understood to have a close working relationship with the Republic of Ireland's Special Detective Unit, the counter-terrorism and counter-intelligence section of the Garda Siochana, particularly with regards to threats from dissident republican terrorism and Islamic terrorism.

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Each organisation works in partnership throughout the investigation, but MI5 retain the lead for collecting, assessing and exploiting intelligence.

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Tasking was reactive, acting at the request of law enforcement bodies such as the National Criminal Intelligence Service, for whom MI5 officers performed electronic surveillance and eavesdropping duties during Operation Trinity.

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In 2001, after the 11 September attacks in the U S, MI5 started collecting bulk telephone communications data under a little understood general power of the Telecommunications Act 1984 .

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In March 2018, the government acknowledged that MI5 officers are allowed to authorise agents to commit criminal activity in the UK.

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In October 2020, Rangzieb Ahmed brought a civil claim against MI5, alleging that Pakistan's Inter-Services Intelligence agency had arrested him in 2006, and that MI5 had colluded in torture by submitting questions which were put to him under torture in Pakistan.

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MI5 was based at Watergate House in the Strand from 1912 until 1916, when it moved to larger facilities at 16 Charles Street for the remaining years of the First World War.

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MI5 is known sometimes to use Government Communications Planning Directorate as a cover name, for example, when sponsoring research.

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