For decades, Britain’s secret services lurked in the shadows, tapping wires, infiltrating enemy threats and gathering information under a veil of secrecy.
But recent decades have seen Britain’s intelligence agencies demystified – at least to a small degree. The 1987 memoir Spycatcher, written by a former intelligence officer, aimed to expose the inner workings of British espionage. And since the late 1980s, MI5 and MI6’s work has been publicly recognised by the British government.
So, we now know that MI5 is responsible for domestic counterespionage, whereas MI6 aims to gather intelligence overseas. In the world of fiction, MI5 has been portrayed in the BBC drama Spooks. And Ian Fleming’s James Bond is a fascinating, if fantastical, depiction of an MI6 agent.
But how far does spy fiction stray from the truth? Here are 10 facts about MI5 and MI6 to shed some light.
1. Queen Elizabeth I’s spymaster was a precursor to MI5
MI5’s earliest antecedent was Sir Francis Walsingham, Queen Elizabeth I’s spymaster from 1573 and 1590.
Fearful of a Catholic uprising, Walsingham recruited informers, cryptographers, and seal-breakers to form a protective spy ring around the Queen. His efforts resulted in, amongst other things, the execution of Mary, Queen of Scots, and a strategic advantage when the Spanish Armada attacked England in 1588.
The rose that Walsingham pressed into his wax seals is referenced on MI5’s coat of arms.
2. MI5 and MI6 were founded at the same time
At the turn of the 20th century, Herbert Asquith’s government became concerned about Germany’s imperial ambitions.
In October 1909, on the Committee of Imperial Defence’s recommendation, the Secret Service Bureau was established. British Army Captain Vernon Kell was responsible for counterespionage, while Royal Navy Captain Mansfield Cumming managed overseas intelligence gathering.
These divisions, the 5th and 6th of military intelligence, grew into MI5 (the Secret Service) and MI6 (the Secret Intelligence Service), respectively.
3. There were 19 military intelligence divisions and 2 were ‘never used’
There have been 17 different military intelligence divisions in Britain – or possibly 19. MI13 and MI18 were supposedly never used, though it’s been speculated that their purposes have simply never been revealed.
Following World War Two, some divisions were disbanded, others transferred to government agencies such as the Ministry of Information and Military Operations, while the vast majority were absorbed into MI5 and MI6, the only 2 divisions currently active.
4. MI6’s headquarters have featured in 4 James Bond films
MI6’s headquarters, the SIS Building, overlooks the Thames at Vauxhall Cross. The building’s architectural influences range from industrial modernism to Aztec temples.
Nicknamed Legoland and Babylon-on-Thames for its layered, block-like structure, the SIS Building has featured in 4 James Bond films: a location in Goldeneye (1995), a bomb target in The World Is Not Enough (1999) and Skyfall (2012), and the subject of a controlled demolition in Spectre (2015).
5. There’s a miniature monorail in MI5’s headquarters
MI5 is based at Thames House, Millbank, in a Grade II-listed building. Once considered Britain’s greatest office building, Thames House includes an automated miniature monorail which transports documents from the basement around the building.
The BBC’s MI5 drama, Spooks, used the exterior of Thames House on multiple occasions but opted for Freemason’s Hall in Covent Garden to depict MI5’s fictional headquarters.
6. MI5 was accused of forging a letter that influenced a general election
MI5 had a controversial impact in the 1924 General Election after ‘intercepting’ a letter inciting British communists to action. It bore the signature of Comintern chairman Gregory Zinoviev.
MI5 officers presented the Zinoviev Letter to Ramsay MacDonald, whose Labour government had just lost a vote of no confidence. And though MacDonald agreed to keep it secret, the letter was leaked to the press.
Published 4 days before the election, the letter negatively impacted both Labour and Liberal Party votes, helping the Conservatives to win a parliamentary majority.
While the Zinoviev Letter’s true author remains unknown, MI5 has repeatedly been accused of forging it.
7. A plan to infiltrate Nazi Germany ultimately backfired
On 9 November 1939, in the Dutch border town of Venlo, a covert British operation went awry. Two British intelligence officers accompanied a Dutch Lieutenant, Dirk Klop, to a meeting with German officials who were supposedly willing to oppose Adolf Hitler and help the Allies. But it was a ruse.
Instructed by SS Commander Heinrich Himmler, the German officers killed Klop and kidnapped the British agents, later extracting covert information from them. The incident was an embarrassment for Britain and a propaganda victory for Germany.
The botched operation ultimately effected sweeping changes within Britain’s intelligence services, with wartime coalition leader Winston Churchill going on to significantly restructure MI5.
8. Double agents were crucial to the success of the D-Day landings
MI6 played a major role in the Normandy landings of 1944. As part of Operation Fortitude, double agents fed Germany misleading information, suggesting landings were planned in Norway and Pas-de-Calais. This caused German troops to overstretch themselves.
With resources under-deployed at Normandy, 875,000 Allied troops crossed the channel in June, significantly aiding the recapture of mainland Europe.
9. MI5 and MI6 were infiltrated by Soviet Spies
During World War Two and the early stages of the Cold War, 5 KGB spies who were also former Cambridge University students – the Cambridge Five – infiltrated British intelligence and passed information to the Soviet Union.
The existence of the Cambridge Five was confirmed when Donald MacLean and Guy Burges fled to the Soviet Union in 1951, followed by Harold ‘Kim’ Philby in 1963. Philby’s desertion eventually prompted confessions from Anthony Blunt and John Cairncross.
The actions of the Cambridge Five caused major international paranoia about Soviet spies. The Five were never prosecuted.
10. MI5 and MI6 stayed ‘secret’ until a whistleblower broke rank
MI5 and MI6 may have remained ‘secret’, or at least significantly sheltered from public view, had it not been for former officer Peter Wright’s 1987 memoir Spycatcher: The Candid Autobiography of a Senior Intelligence Officer.
The book featured many damning allegations, such as former MI5 Director General Sir Roger Hollis being a Soviet mole, and MI5 and the CIA having planned to overthrow Prime Minister Harold Wilson.
The British government blocked publication of Sypcatchertwice. Ultimately, though, the memoir sold over 2 million copies, forcing Margaret Thatcher’s government to finally publicly acknowledge MI5 and MI6’s work in the 1989 Secret Services Act.