Secret Intelligence Service
|Jurisdiction||Her Majesty's Government|
|Headquarters||SIS Building, London, UK
|Motto||Semper Occultus (Always Secret)|
|Employees||3,200 (fy 2012–13)|
|Annual budget||Single Intelligence Account (£2.3 billion in 2010–2011 financial year)|
The Secret Intelligence Service (SIS), commonly known as MI6 (Military Intelligence, Section 6), is the British intelligence agency which supplies the British Government with foreign intelligence. (Similarly, MI5 supplies the British Government with internal British intelligence.) MI6 operates under the formal direction of the Joint Intelligence Committee (JIC) alongside the internal Security Service (MI5), the Government Communications Headquarters (GCHQ) and Defence Intelligence (DI).
SIS is frequently referred to by the name MI6 (Military Intelligence, Section 6), a name used as a flag of convenience during the First World War when it was known by many names. The existence of the SIS was not officially acknowledged until 1994.
In late 2010, the head of the SIS delivered what he said was the first public address by a serving chief of the agency in its then 101-year history. The remarks of Sir John Sawers primarily focused on the relationship between the need for secrecy and the goal of maintaining security within Britain. His remarks acknowledged the tensions caused by secrecy in an era of leaks and pressure for ever-greater disclosure.
History and development
The service derived from the Secret Service Bureau, which was founded in 1909. The Bureau was a joint initiative of the Admiralty and the War Office to control secret intelligence operations in the UK and overseas, particularly concentrating on the activities of the Imperial German Government. The bureau was split into naval and army sections which, over time, specialised in foreign espionage and internal counter-espionage activities respectively. This specialisation was because the Admiralty wanted to know the maritime strength of the Imperial German Navy. This specialisation was formalised before 1914. During the First World War in 1916, the two sections underwent administrative changes so that the foreign section became the Directorate of Military Intelligence Section 6 (MI6), the name by which it is frequently known in popular culture today.
Its first director was Captain Sir George Mansfield Smith-Cumming, who often dropped the Smith in routine communication. He typically signed correspondence with his initial C in green ink. This usage evolved as a code name, and has been adhered to by all subsequent directors of SIS when signing documents to retain anonymity.
First World War
The service's performance during the First World War was mixed, because it was unable to establish a network in Germany itself. Most of its results came from military and commercial intelligence collected through networks in neutral countries, occupied territories, and Russia.
After the war, resources were significantly reduced but during the 1920s, SIS established a close operational relationship with the diplomatic service. In August 1919 Cumming created the new passport control department, providing diplomatic cover for agents abroad. The post of Passport Control Officer provided operatives with diplomatic immunity.
The debate over the future structure of British Intelligence continued at length after the end of hostilities but Cumming managed to engineer the return of the Service to Foreign Office control. At this time, the organisation was known in Whitehall by a variety of titles including the Foreign Intelligence Service, the Secret Service, MI1(c), the Special Intelligence Service and even C's organisation. Around 1920, it began increasingly to be referred to as the Secret Intelligence Service (SIS), a title that it has continued to use to the present day and which was enshrined in statute in the Intelligence Services Act 1994.
In the immediate post-war years under Sir George Mansfield Smith-Cumming and throughout most of the 1920s, the SIS was focused on Communism, in particular, Russian Bolshevism. Examples include a thwarted operation to overthrow the Bolshevik government in 1918 by SIS agents Sidney George Reilly and Sir Robert Bruce Lockhart, as well as more orthodox espionage efforts within early Soviet Russia headed by Captain George Hill.
Smith-Cumming died suddenly at his home on 14 June 1923, shortly before he was due to retire, and was replaced as C by Admiral Sir Hugh "Quex" Sinclair. Sinclair created the following sections:
- A central foreign counter-espionage Circulating Section, Section V, to liaise with the Security Service to collate counter-espionage reports from overseas stations.
- An economic intelligence section, Section VII, to deal with trade, industrial and contraband.
- A clandestine radio communications organisation, Section VIII, to communicate with operatives and agents overseas.
- Section N to exploit the contents of foreign diplomatic bags
- Section D to conduct political covert actions and paramilitary operations in time of war. Section D would organise the Home Defence Scheme resistance organisation in the UK and come to be the foundation of the Special Operations Executive (SOE) during the Second World War. 
Second World War
- The cryptanalytic effort undertaken by the Government Code and Cypher School (GC&CS), the bureau responsible for interception and decryption of foreign communications at Bletchley Park.
- The extensive "double-cross" system run by MI5 to feed misleading intelligence to the Germans
- Imagery intelligence activities conducted by the RAF Photographic Reconnaissance Unit (now JARIC, The National Imagery Exploitation Centre).
MI6 assisted the Reichssicherheitshauptamt Amt IV (usually known as Gestapo) via "the exchange of information about Communism", and as late as October 1937. The Reichssicherheitshauptamt (or RSHA) was the infamous organization subordinated to Heinrich Himmler, and it was a branch of the SS organization. From 1939 to 1945, the Gestapo was led by the SS-Gruppenführer und Generalleutnant der Polizei Heinrich Müller. The head of the British agency's Berlin station, Frank Foley, described his relationship with Müller's so-called communism expert as "cordial".
The most significant failure of the service during the war was known as the Venlo incident, named for the Dutch town where much of the operation took place. Agents of the German army secret service, the Abwehr, and the counter-espionage section of the Sicherheitsdienst (SD), posed as high-ranking officers involved in a plot to depose Hitler. In a series of meetings between SIS agents and the 'conspirators', SS plans to abduct the SIS team were shelved due to the presence of Dutch police. On the night of 8–9 November 1939, a meeting took place without police presence. There, the two SIS agents were duly abducted by the SS.
In 1940, journalist and Soviet agent Kim Philby applied for a vacancy in Section D of SIS, and was vetted by his friend and fellow Soviet agent Guy Burgess. When Section D was absorbed by Special Operations Executive (SOE) in summer of 1940, Philby was appointed as an instructor in the arts of "black propaganda" at the SOE's training establishment in Beaulieu, Hampshire.
In early 1944 MI6 re-established Section IX, its prewar anti-Soviet section, and Philby took a position there. He was able to alert the NKVD about all British intelligence on the Soviets—including what the American OSS had shared with the British about the Soviets.
Despite these difficulties the service nevertheless conducted substantial and successful operations in both occupied Europe and in the Middle East and Far East where it operated under the cover name Interservice Liaison Department (ISLD).
In August 1945 Russian intelligence officer Konstantin Volkov tried to defect to Britain, offering the names of all Soviet agents working inside British intelligence. Philby received the memo on Volkov's offer, and alerted the Soviets so they could arrest him. In 1946, SIS absorbed the "rump" remnant of the Special Operations Executive (SOE), dispersing the latter's personnel and equipment between its operational divisions or "controllerates" and new Directorates for Training and Development and for War Planning. The 1921 arrangement was streamlined with the geographical, operational units redesignated "Production Sections", sorted regionally under Controllers, all under a Director of Production. The Circulating Sections were renamed "Requirements Sections" and placed under a Directorate of Requirements.
SIS operations against the USSR were extensively compromised by the fact that the post-war Counter-Espionage Section, R5, was headed for two years by an agent working for the Soviet Union, Harold Adrian Russell "Kim" Philby. Although Philby's damage was mitigated for several years by his transfer as Head of Station in Turkey, he later returned and was the SIS intelligence liaison officer at the Embassy in Washington D.C. In this capacity he compromised a programme of joint US-UK paramilitary operations (Albanian Subversion, Valuable Project) in Enver Hoxha's Albania (although it has been shown that these operations were further compromised "on the ground" by poor security discipline among the Albanian émigrés recruited to undertake the operations). Philby was eased out of office and quietly retired in 1953 after the defection of his friends and fellow members of the "Cambridge spy ring" Donald Duart Maclean and Guy Burgess.
SIS suffered further embarrassment when it turned out that an officer involved in both the Vienna and Berlin tunnel operations had been turned as a Soviet agent during internment by the Chinese during the Korean War. This agent, George Blake, returned from his internment to be treated as something of a hero by his contemporaries in "the office". His security authorisation was restored, and in 1953 he was posted to the Vienna Station where the original Vienna tunnels had been running for years. After compromising these to his Soviet controllers, he was subsequently assigned to the British team involved on Operation Gold, the Berlin tunnel, and which was, consequently, blown from the outset. In 1956 MI6 Director John Alexander Sinclair had to resign after the botched affair of the death of Lionel Crabb.
SIS activities included a range of covert political actions, including the overthrow of Mohammed Mossadeq in Iran in the 1953 Iranian coup d'état (in collaboration with the US Central Intelligence Agency).
Despite earlier Soviet penetration, SIS began to recover as a result of improved vetting and security, and a series of successful penetrations. From 1958, SIS had three moles in the Polish UB, the most successful of which was codenamed NODDY. The CIA described the information SIS received from these Poles as "some of the most valuable intelligence ever collected", and rewarded SIS with $20 million to expand their Polish operation. In 1961 Polish defector Michael Goleniewski exposed George Blake as a Soviet agent. Blake was identified, arrested, tried for espionage and sent to prison. He escaped and was exfiltrated to the USSR in 1966.
Also, in the GRU, they recruited Colonel Oleg Penkovsky. Penkovsky ran for two years as a considerable success, providing several thousand photographed documents, including Red Army rocketry manuals that allowed US National Photographic Interpretation Center (NPIC) analysts to recognise the deployment pattern of Soviet SS4 MRBMs and SS5 IRBMs in Cuba in October 1962. SIS operations against the USSR continued to gain pace through the remainder of the Cold War, arguably peaking with the recruitment in the 1970s of Oleg Gordievsky whom SIS ran for the better part of a decade, then successfully exfiltrated from the USSR across the Finnish border in 1985.
The real scale and impact of SIS activities during the second half of the Cold War remains unknown, however, because the bulk of their most successful targeting operations against Soviet officials were the result of "Third Country" operations recruiting Soviet sources travelling abroad in Asia and Africa. These included the defection to the SIS Tehran Station in 1982 of KGB officer Vladimir Kuzichkin, the son of a senior Politburo member and a member of the KGB's internal Second Chief Directorate who provided SIS and the British government with warning of the mobilisation of the KGB's Alpha Force during the 1991 August Coup which briefly toppled Soviet leader Mikhail Gorbachev.
After the Cold War
The end of the Cold War led to a reshuffle of existing priorities. The Soviet Bloc ceased to swallow the lion's share of operational priorities, although the stability and intentions of a weakened but still nuclear-capable Federal Russia constituted a significant concern. Instead, functional rather than geographical intelligence requirements came to the fore such as counter-proliferation (via the agency's Production and Targeting, Counter-Proliferation Section) which had been a sphere of activity since the discovery of Pakistani physics students studying nuclear-weapons related subjects in 1974; counter-terrorism (via two joint sections run in collaboration with the Security Service, one for Irish republicanism and one for international terrorism); counter-narcotics and serious crime (originally set up under the Western Hemisphere Controllerate in 1989); and a 'global issues' section looking at matters such as the environment and other public welfare issues. In the mid-1990s these were consolidated into a new post of Controller, Global and Functional.
During the transition, then-C Sir Colin McColl embraced a new, albeit limited, policy of openness towards the press and public, with 'public affairs' falling into the brief of Director, Counter-Intelligence and Security (renamed Director, Security and Public Affairs). McColl's policies were part and parcel with a wider 'open government initiative' developed from 1993 by the government of John Major. As part of this, SIS operations, and those of the national signals intelligence agency, GCHQ, were placed on a statutory footing through the 1994 Intelligence Services Act. Although the Act provided procedures for Authorisations and Warrants, this essentially enshrined mechanisms that had been in place at least since 1953 (for Authorisations) and 1985 (under the Interception of Communications Act, for warrants). Under this Act, since 1994, SIS and GCHQ activities have been subject to scrutiny by Parliament's Intelligence and Security Committee.
During the mid-1990s the British intelligence community was subjected to a comprehensive costing review by the Government. As part of broader defence cut-backs SIS had its resources cut back 25% across the board and senior management was reduced by 40%. As a consequence of these cuts, the Requirements division (formerly the Circulating Sections of the 1921 Arrangement) were deprived of any representation on the board of directors. At the same time, the Middle East and Africa Controllerates were pared back and amalgamated. According to the findings of Lord Butler of Brockwell's Review of Weapons of Mass Destruction, the reduction of operational capabilities in the Middle East and of the Requirements division's ability to challenge the quality of the information the Middle East Controllerate was providing weakened the Joint Intelligence Committee's estimates of Iraq's non-conventional weapons programmes. These weaknesses were major contributors to the UK's erroneous assessments of Iraq's 'weapons of mass destruction' prior to the 2003 invasion of that country.
In the run up to the invasion of Iraq in 2003, it is alleged, although not confirmed, that some SIS conducted Operation Mass Appeal which was a campaign to plant stories about Iraq's WMDs in the media. The operation was exposed in the Sunday Times in December 2003. Claims by former weapons inspector Scott Ritter suggest that similar propaganda campaigns against Iraq date back well into the 1990s. Ritter claims that SIS recruited him in 1997 to help with the propaganda effort. "The aim was to convince the public that Iraq was a far greater threat than it actually was."
On 6 May 2004 it was announced that Sir Richard Dearlove was to be replaced as head of the SIS by John Scarlett, former chairman of the Joint Intelligence Committee. Scarlett was an unusually high-profile appointment to the job, and gave evidence at the Hutton Inquiry.
On 15 November 2006, SIS allowed an interview with current operations officers for the first time. The interview was on the Colin Murray show on BBC Radio 1. The two officers (one male and one female) had their voices disguised for security reasons. The officers compared their real experience with the fictional portrayal of SIS in the James Bond films. While denying that there ever existed a "licence to kill" and reiterating that SIS operated under British law, the officers confirmed that there is a 'Q'-like figure who is head of the technology department, and that their director is referred to as 'C'. The officers described the lifestyle as quite glamorous and very varied, with plenty of overseas travel and adventure, and described their role primarily as intelligence gatherers, developing relationships with potential sources.
Sir John Sawers became head of the SIS in November 2009, the first outsider to head SIS in more than 40 years. Sawers came from the Diplomatic Service, previously having been the British Permanent Representative to the United Nations.
During the global war on terror, SIS accepted information from the CIA that was obtained through torture, including the extraordinary rendition program. Craig Murray, a UK ambassador to Uzbekistan, had written several memos critical of the UK's accepting this information; he was then fired from his job.
In July 2011 it was reported that SIS has closed several of its stations in the past couple of years, particularly in Iraq, where it used to have several outposts in the south of the country in the region of Basra according to the annual report of the parliamentary Intelligence and Security Committee. The closures have allowed the service to focus its attention on Pakistan and Afghanistan, which are its principal stations. On 16 November 2011 SIS warned the national transitional council in Benghazi after discovering details of planned strikes, said foreign secretary William Hague. 'The agencies obtained firm intelligence, were able to warn the NTC of the threat, and the attacks were prevented,’ he said. In a rare speech on the intelligence agencies, he praised the key role played by SIS and GCHQ in bringing Gaddafi’s 42-year dictatorship to an end, describing them as 'vital assets' with a 'fundamental and indispensable role' in keeping the nation safe. 'They worked to identify key political figures, develop contacts with the emerging opposition and provide political and military intelligence. 'Most importantly, they saved lives,’ he said. The speech follows criticism that SIS had been too close to the Libyan regime and was involved in the extraordinary rendition of anti-Gaddafi activists. Mr Hague also defended controversial proposals for secrecy in civil court involving intelligence material.
The Daily Star reported in November 2011 that SIS helped capture Saif al-Islam Gaddafi. The top-secret mission, dubbed Operation X to disguise its purpose, used modern electronic intelligence (ELINT) technologies to bug him along with his friends and family. Gaddafi had been hiding out in the desert for a month but the breakthrough came when he made two phone calls, one after the other, to say he was safe. It allowed the joint British and French bugging operation to pinpoint his location. SIS agents using the £25million top-secret equipment closed in on him before calling in the Libyan snatch squad to apprehend him.
In February 2013 Channel Four News reported on evidence of MI6 spying on opponents of the Gaddafi regime and handing the information to the regime in Libya. The files looked at contained "a memorandum of understanding, dating from October 2002, detailing a two-day meeting in Libya between Gaddafi's external intelligence agency and two senior heads of MI6 and one from MI5 outlining joint plans for "intelligence exchange, counter terrorism and mutual co-operation".
Since 1995, SIS headquarters has been at 85 Vauxhall Cross, along the Albert Embankment in Vauxhall on the banks of the River Thames by Vauxhall Bridge, London. Previous headquarters have been Century House, 100 Westminster Bridge Road, Lambeth (1966–95); and 54, Broadway, off Victoria Street, London (1924–66). (Although SIS operated from Broadway, it was actually based at St James's Street and also made considerable use of the adjoining St Ermin's Hotel).
The building was designed by Sir Terry Farrell and built by John Laing. The developer Regalian Properties approached the Government in 1987 to see if they had any interest in the proposed building. At the same time, MI5 was seeking alternative accommodation and co-location of the two services was studied. In the end this proposal was abandoned due to the lack of buildings of adequate size (existing or proposed) and the security considerations of providing a single target for attacks. In December 1987, Prime Minister Margaret Thatcher's Government approved the purchase of the new building for the SIS.
The building design was reviewed to incorporate the necessary protection for Britain's foreign intelligence gathering agency. This includes overall increased security, extensive computer suites, technical areas, bomb blast protection, emergency back-up systems and protection against electronic eavesdropping. While the details and cost of construction have been released, about ten years after the original National Audit Office (NAO) report was written, some of the service's special requirements remain classified. The NAO report Thames House and Vauxhall Cross has certain details omitted, describing in detail the cost and problems of certain modifications, but not what these are. Rob Humphrey's London: The Rough Guide suggests one of these omitted modifications is a tunnel beneath the Thames to Whitehall. The NAO put the final cost at £135.05m for site purchase and the basic building, or £152.6m including the service's special requirements.
The setting of the SIS offices was featured in the James Bond films GoldenEye, The World Is Not Enough, Die Another Day and Skyfall. SIS allowed filming of the building itself for the first time in The World is Not Enough for the pre-credits sequence, where a bomb hidden in a briefcase full of money is detonated inside the building. A Daily Telegraph article claimed that the British government opposed the filming, but these claims were denied by a Foreign Office spokesperson. In Skyfall the building is once again attacked by an explosion, this time by a cyber attack turning on a gas line and igniting the fumes, after which MI6 operations are moved to a secret underground facility.
On the evening of 20 September 2000, the building was attacked using a Russian-built RPG-22 anti-tank rocket. Striking the eighth floor, the missile caused only superficial damage. The Anti-Terrorist branch of the Metropolitan Police attributed responsibility to the Real IRA.
Most other buildings are held or nominally occupied by the Foreign & Commonwealth Office. They include:
- Hanslope Park: on the outskirts of Milton Keynes housing the Her Majesty's Government Communications Centre, which supports the Foreign & Commonwealth Office and the British intelligence community.
- Fort Monckton: a former Napoleonic War fort, rebuilt in the 1880s, is now the field operations training centre for SIS.
MI6 is nicknamed The Circus. Some say this was coined by John le Carré in his espionage novels. Leo Marks in his autobiographical Between Silk and Cyanide explains that the name arose because a section of Britain's WWII SOE was housed in a building at 1 Dorset Square, London, which had formerly belonged to the directors of Bertram Mills circus. "This inspired continuity was one of SOE's favourite in-jokes."
- 1909–1923: Sir Mansfield Smith-Cumming, KCMG CB
- 1923–1939: Admiral Sir Hugh Sinclair, KCB
- 1939–1952: Major General Sir Stewart Menzies, KCB KCMG DSO MC
- 1953–1956: Sir John Alexander Sinclair, KCMG CB OBE
- 1956–1968: Sir Richard White, KCMG KBE
- 1968–1973: Sir John Rennie, KCMG
- 1973–1978: Sir Maurice Oldfield, GCMG CBE
- 1979–1982: Sir Dick Franks, KCMG
- 1982–1985: Sir Colin Figures, KCMG OBE
- 1985–1989: Sir Christopher Curwen, KCMG
- 1989–1994: Sir Colin McColl, KCMG
- 1994–1999: Sir David Spedding, KCMG CVO OBE
- 1999–2004: Sir Richard Dearlove, KCMG OBE
- 2004–2009: Sir John Scarlett, KCMG OBE
- 2009–2014: Sir John Sawers, KCMG
- 2014–Present: Alex Younger, CMG
- List of intelligence agencies
- Cambridge Five, a Cold War Soviet spy ring
- Anthony Blunt (cryptonym: Johnson), MI5 officer and Soviet agent
- Guy Burgess (cryptonym: Hicks), SIS officer and Soviet agent
- John Cairncross (cryptonym: Liszt), SIS officer and Soviet agent
- Donald Maclean (cryptonym: Homer), SIS officer and Soviet agent
- Kim Philby (cryptonym: Stanley), SIS officer and Soviet agent
- James Bond, 007, a fictional character from the popular book, movie and video game franchise, who is said to work for MI6
- David Cornwell (John le Carré), author, former SIS officer
- Charles Cumming, author
- Paul Dukes, SIS officer and author
- Ian Fleming, author of James Bond novels, former NID officer
- Graham Greene, author, former SIS officer
- Ralph Izzard, journalist, author, former NID officer
- Horst Kopkow, SS officer who worked for SIS after the Second World War
- Alec Leamas, fictional SIS (or "the Circus" in the novels) operative in John Le Carré's Spy Who Came in from the Cold (1963) and portrayed by Richard Burton in the 1965 film
- Sidney Reilly, Ace of Spies, worked for SIS and others
- Alex Rider, fictional agent, unwillingly working for MI6, character in British author Anthony Horowitz’s Alex Rider series
- Alan Blunt, fictional head of Special Operations Division, MI6, character in British author Anthony Horowitz’s Alex Rider series
- Mrs. Jones, fictional deputy head of Special Operations Division, MI6, immediate superior is Alan Blunt
- Ian Rider, fictional agent, uncle of Alex Rider and brother of John Rider
- John Rider, fictional agent, father of Alex Rider and brother of Ian Rider
- Krystyna Skarbek, agent
- George Smiley, a fictional character from the popular books of John Le Carré and movie franchise, who works for MI6
- Richard Tomlinson, author, former SIS officer
- Valentine Vivian, Vice-Chief of the SIS and head of counter-espionage, Section V
- Gareth Williams, seconded to SIS from GCHQ, likely to have been unlawfully killed
- Intelligence and Security Committee of Parliament Annual Report 2012–2013 (PDF). 2013. p. 40. ISBN 978-0-10-298652-5. Retrieved 29 December 2013.
- "Funding and Financial Controls". SIS – MI6. Retrieved 10 November 2014.
- "The Chief". SIS – MI6. Retrieved 10 November 2014.
- "SIS Or MI6. What's in a Name?". SIS website. Retrieved 11 July 2008.
- Whitehead, Jennifer (13 October 2005). "MI6 to boost recruitment prospects with launch of first website". Brand Republic. Retrieved 10 July 2010.
- Burns, John F. et al. "Defending Secrecy, British Spy Chief Goes Public,". The New York Times, 28 October 2010.
- MI6 boss Sir John Scarlett still signs letters in green ink, Matthew Moore, The Daily Telegraph, 27 July 2009
- The usage inspired Ian Fleming in his James Bond novels to use the denominator M for the head of service.
- MI6 (British Secret Intelligence Service), K. Lee Lerner and Hudson Knight in Encyclopedia of Espionage, Intelligence, and Security. Accessed:2007-09-02.
- "C": The Secret Life of Sir Stewart Graham Menzies, Spymaster to Winston Churchill, Anthony Cave Brown, Collier, 1989
- Richard B. Spence, Trust No One: The Secret World Of Sidney Reilly; 2002, Feral House, ISBN 0-922915-79-2.
- Andrew Cook, Ace of Spies: The True Story of Sidney Reilly; 2004, Tempus Publishing, ISBN 0-7524-2959-0.
- Robert Bruce Lockhart, Memoirs of a British Agent (reprint); 2003, Folio Society, ASIN B000E4QXIK.
- Atkin, Malcolm (2015). Fighting Nazi Occupation: British Resistance 1939 - 1945. Barnsley: Pen and Sword. pp. Chapter 4. ISBN 978-1-47383-377-7.
- Follett, Ken; Money, Paper (27 December 1987). "The Oldest Boy of British Intelligence". The New York Times. Retrieved 1 July 2012.
- "GCHQ releases Alan Turing's secret wartime papers". 20 April 2012. Retrieved 1 July 2012.
- Jeffery 2010, p. 302.
- "Affidavit of Walter Schellenburg". Nazi Conspiracy and Aggression. Volume VII. USGPO, Washington, 1946/pp.622–629. Document UK-81 (Washington). 1946. Retrieved 6 October 2010.
- "Beaulieu". Pen & Sword Books. Retrieved 1 July 2012.
- "Kim Philby – new Russian god?". International News Analysis Today. 20 December 2010. Retrieved 1 July 2012.
- World War II: The Underground War. Library of Congress. p. 711. Retrieved 1 July 2012.
- Berg, Sanchia (13 December 2008). "Churchill's secret army lived on". BBC – Today. Retrieved 13 March 2009.
- "The Cambridge Spies". BBC. Retrieved 1 July 2012.
- "Mystery of missing frogman deepens". BBC News. 9 May 1956. Retrieved 1 July 2012.
- "Licence to kill: When governments choose to assassinate". BBC. 17 March 2012. Retrieved 1 July 2012.
- Shaun McCormack (2003). Inside Britain's MI6: Military Intelligence 6. The Rosen Publishing Group. p. 28. ISBN 0-8239-3812-3.
- "George Blake". History Learning. Retrieved 1 July 2012.
- "The spy who loved us – Oleg Penkovsky". Washington Monthly. May 1992. Retrieved 1 July 2012.
- "What every good spy should know". The Guardian (London). 28 April 2000. Retrieved 1 July 2012.
- "The Soviets: Coups and Killings in Kabul". Time. 22 November 1982. Retrieved 1 July 2012.
- "Intelligence Services Act 1994" (PDF). UK Parliament. Retrieved 1 July 2012.
- "Review of Intelligence on weapons of mass destruction" (PDF). London: Committee led by Lord Butler. Retrieved 1 July 2012.
- Revealed: how SIS sold the Iraq war, Sunday Times, 28 December 2003
- MI6 ran 'dubious' Iraq campaign, BBC, 21 November 2003
- Scott Ritter, Sunday Times, 28 December 2003
- "Hutton Inquiry: Day 9: John Scarlett gives evidence". NFO. Retrieved 1 July 2012.
- Johnston, Philip (16 November 2006). "MI6 licensed to thrill listeners to Radio 1". The Daily Telegraph (London). Retrieved 1 July 2012.
- Michael Evans (16 June 2009). "Outsider Sir John Sawers appointed new head of MI6". The Times. Retrieved 16 June 2009.
- Dirty Diplomacy, 2007, Craig Murray, Scribner.
- "Romanian president meet with British MI6 head in London". BBC Monitoring International Reports. 9 June 2011. Retrieved 1 July 2012.
- Radnedge, Aidan. "MI6 thwarted attacks on Libya rebel forces by Gaddafi regime". Metro. Retrieved 28 December 2011.
- Sherwood, Deborah (20 November 2011). "Simply The Best 7 Days A Week :: News :: Gaddafi’s son snared by MI6". Daily Star. Retrieved 28 December 2011.
- New evidence of UK complicity in libya torture Channel Four News, 8 February 2013
- Construction information
- Thames House and Vauxhall Cross, Report by the Comptroller and Auditor General, 18 February 2000
- "Bond is backed... by the government". The Guardian (London). 27 April 1999. Retrieved 29 December 2007.
- "'Rocket' theory over MI6 blast". BBC. 21 September 2000. Retrieved 1 July 2012.
- Ian Cobain and Richard Norton-Taylor (18 April 2012). "Sins of colonialists lay concealed for decades in secret archive". The Guardian (London). Retrieved 25 June 2012.
- Richard Tomlinson (2001). The Big Breach: From Top Secret to Maximum Security. Mainstream Publishing. ISBN 1-903813-01-8.
- Marks, Leo (2007). Between Silk and Cyanide. The History Press. p. 21. ISBN 978-0750948357.
- Aldrich, Richard J. (2006), The Hidden Hand: Britain, America and Cold War Secret Intelligence, London: John Murray ISBN 1-58567-274-2
- Atkin, Malcolm (2015). Fighting Nazi Occupation: British Resistance 1939 - 1945. Barnsley: Pen and Sword. ISBN 978-1-47383-377-7.
- Davies, Philip H.J. (2004). MI6 and the Machinery of Spying London: Frank Cass, ISBN 0-7146-8363-9 (h/b)
- Davies, Philip H.J. (2005) 'The Machinery of Spying Breaks Down' in Studies in Intelligence Summer 2005 Declassified Edition.
- Dorril, Stephen (2001) MI6: Fifty Years of Special Operations London: Fourth Estate, ISBN 1-85702-701-9
- Humphreys, Rob (1999) London: The Rough Guide, Rough Guides, ISBN 1-85828-404-X
- Jeffery, Keith (2010). MI6: The History of the Secret Intelligence Service, 1909–1949. London: Bloomsbury. ISBN 978-0-7475-9183-2.
- Judd, Alan (1999) The quest for C : Sir Mansfield Cumming and the founding of the British Secret Service, London: HarperCollins, ISBN 0-00-255901-3
- Seeger, Kirsten Olstrup (2008) 'Friendly Fire' (DK) ISBN 978-87-7799-193-6. A biography of the author's father who was a member of the Danish resistance during the Second World War.
- Smith, Michael (2010) SIX: A History of Britain's Secret Intelligence Service Pt 1 Murder and Mayhem 1909–1939, London: Dialogue, ISBN 978-1-906447-00-7
- Smiley, Colonel David (1994). Irregular Regular. Norwich: Editions Michael Russell. ISBN 0-85955-202-0. An autobiography of a British officer, honorary colonel of the Royal Horse Guards, David de Crespigny Smiley LVO, OBE, MC, who served in the Special Operations Executive during World War II (Albania, Thailand) and was a MI6 officer after war (Poland, Malta, Oman, Yemen). Translated in French by Thierry Le Breton, Au cœur de l’action clandestine. Des Commandos au MI6, L’Esprit du Livre Editions, France, 2008 ISBN 2915960275
- Tomlinson, Richard; Nick Fielding (2001). The Big Breach: From Top Secret to Maximum Security. Mainstream Publishing ISBN 1-903813-01-8
- Walton, Calder (2012). Empire of Secrets. London: Harperpress. ISBN 978-0007457960
- Colonna Vilasi, A. (2013) The History of MI-6, Penguin Group Publishing, UK/USA Release
|Wikimedia Commons has media related to Secret Intelligence Service of the United Kingdom.|
- Official website
- UK Intelligence Community On Line
- "Information about SIS". Archived from the original on 25 August 2007. from the Foreign and Commonwealth Office's website
- BBC interview with MI6 spy. BBC's The One show presenter interviews MI6 spy