Harold Adrian Russell “Kim” Philby (1912-1988) was the most damaging of the Cambridge spies, the group of British men recruited by Soviet intelligence in the 1930s. Born in Ambala, India, and educated at Trinity College, Cambridge, he was recruited by Soviet intelligence in 1934. He joined the Secret Intelligence Service (SIS, or MI6) in 1940 and in 1944 was placed in charge of its new section for counterintelligence against the Soviet Union, giving Moscow insight into British operations aimed at the USSR.

From 1949 to 1951 Philby served as SIS liaison in Washington with the CIA and FBI. After his friends Guy Burgess and Donald Maclean fled to Moscow in May 1951, he came under suspicion and left SIS, but in 1955 the British government publicly said it had no evidence he was the “third man.” He later worked in Beirut as a journalist and defected to the Soviet Union in January 1963. He lived in Moscow until his death in May 1988 and published a memoir, My Silent War, in 1968. Philby’s career remains the classic case of a hostile service penetrating the counterintelligence apparatus built to stop it.

Sources

• Philby, Kim. My Silent War. MacGibbon & Kee, 1968.
• Andrew, Christopher, and Vasili Mitrokhin. The Sword and the Shield: The Mitrokhin Archive and the Secret History of the KGB. Basic Books, 1999.
• Macintyre, Ben. A Spy Among Friends: Kim Philby and the Great Betrayal. Crown, 2014.

Summary entry. A fuller, document-based profile is in preparation.