The photographer who talent-spotted Kim Philby operated as a Soviet courier and technical asset for decades, her full role kept secret until MI5 interrogated her in 1952.
He handled the crown jewel of the double-cross system while socializing with the Cambridge Five; his name remained in the security files until a car crash in 1964.
A man who ran Britain's wartime Soviet relations spent decades feeding Moscow from the heart of the Ministry of Information, a betrayal confirmed by papers left in a defector's luggage.
The Security Service tracked the flight of two diplomats to Moscow, but the true cost of the Foreign Office's leaked telegrams in Washington remains buried in the gaps of the record.
A British diplomat deceived his peers and compromised the West for two decades, a betrayal documented in a Security Service file containing interviews with his former friends.
British diplomats and intelligence officers were left blind and demoralized after Guy Burgess spent two decades as a Soviet mole before vanishing into the East.
British diplomats were blindsided when Guy Burgess vanished in 1951, leaving behind a legacy of Soviet infiltration that scarred the Anglo-American alliance for decades.
They operated within the highest circles of the Foreign Office for twenty years before vanishing into the Soviet Union in May 1951, leaving a trail of aliases and broken trust.
British diplomats lived double lives for two decades before fleeing to the USSR in 1951; the Security Service files record the aliases used to hide their betrayal.
His 1951 disappearance with Donald Maclean shattered trust between London and Washington, while his aliases kept the Security Service in the dark for decades.
Foreign Office elites deceived their colleagues for two decades, leaking Washington secrets before fleeing to Moscow; their names now sit in the Security Service’s PF Series files.
A high-flying diplomat's double life stayed hidden for two decades until he fled to the USSR in 1951, leaving behind a trail of leaks from the Washington Embassy.
A high-ranking diplomat and his American wife spent decades hiding behind a web of seven aliases, betraying the British Foreign Office to Moscow before vanishing in 1951.
Secrets from the Washington Embassy were funneled to Moscow for twenty years by a man the Foreign Office considered a rising star, a betrayal that ended in a sudden flight to the USSR.