Gordievskij was considered to be Britain's most valuable spy within the Russian intelligence service ever, reports BBC. He worked for the Soviet KGB when he was recruited and sent important information to both MI6 and MI5 during his many years as a double agent – which, among other things, led to 25 Soviet spies being forced to leave the country.
One of his greatest achievements is considered to be when he, in the early 1980s, warned that Moscow had become so paranoid about an imagined nuclear attack that they began preparing to strike first. The information contributed to the leaders of the Western world toning down their rhetoric, and the crisis was averted.
Furthermore, he revealed the main person in one of Sweden's largest spy scandals: Stig Bergling. In 1977, Oleg Gordievskij notified his British employers that the Soviet Union had managed to recruit a spy in Sweden, writes Expressen. Bergling was already suspected, but Gordievskij's detailed information contributed to the Swedish spy being caught and put on trial.
However, in 1985, suspicions were raised against Gordievskij in Moscow, and he barely escaped being caught by being smuggled across the border to Finland in the trunk of a car.
Oleg Gordievskij was 86 years old and died in his home in Surrey, England, according to BBC.
