GREAT BRITISH SPYING: A TIMELINE

1909: the founding of MI6

The Secret Service Bureau (later MI6) was founded by prime minister Herbert Asquith to counter an increasingly powerful and militaristic Germany. Its first director, Captain Sir Mansfield George Smith-cumming, famously signed letters with his initial ‘C’ in green ink, a tradition adopted by all subsequent MI6 directors.

1944: wartime double-crossing

Double-agents helped to deceive Hitler that the D-day invasion would strike at Calais, not Normandy. The operation – directed by the Twenty Committee – was named ‘‘double cross’’ after the Roman numerals for the number 20.

1950s: the Cambridge Five

Kim Philby, right, Guy Burgess, Donald Maclean, Anthony Blunt and John Cairncross had bonded over their shared love of Marxismleninism. After graduating, some became diplomats and others became agents for MI5 and MI6, but all were eventually recruited by the Soviet Union as double agents. They passed information to the KGB until the early 1950s – even Blunt, who curated art in Buckingham Palace and knew the Queen personally. The public did not learn the full extent of their espionage until 1979.

1978: the umbrella assassination

On September 7 1978, Georgi Markov, a Bulgarian playwright who had just defected to the West, was walking over London’s Waterloo Bridge when he felt a sting on the back of his right thigh, like an insect bite. He saw a man with an umbrella hurrying into a taxi. By the time he arrived at work, a red rash had developed; within four days, he was dead. His assassin used the umbrella to inject Markov with a pellet containing platinum and iridium – and was never caught.

2017: cyber attacks

Ransomware technology called Wannacry launched cyber attacks on computers across the world. The IT system used by the NHS was particularly badly hit; some GPS were unable to access patient data, and ambulances were diverted from hospitals in some areas. Experts credit one British researcher, Marcus Hutchins, 23, with finding the “kill switch” to shut down the attack, which was believed to have been launched from North Korea.

2018: Salisbury poisoning

On March 4 2018, Sergei Skripal – a former Russian agent who worked for British intelligence in the

1990s – enjoyed

Sunday lunch with his daughter, Yulia, in Salisbury. A few hours later, both were found unconscious on a public bench, poisoned with the nerve agent Novichok; a perfume bottle containing the deadly substance was later discovered in a bin. Coming 12 years after the fatal poisoning of Russian defector Alexander Litvinenko in London, it demonstrated the new aggression of the Putin regime. Both Skripals survived, but Dawn Sturgess – a local woman thought to have picked up an item containing Novichok – died four months later.