The Cambridge Five was a group of British spies who operated as double agents during the mid-20th century. They were recruited by Soviet intelligence services and provided classified information to the Soviet Union. They were all graduates of the University of Cambridge, and their activities remained largely secret until the 1950s and 1960s. The key members of the Cambridge Five were:
Perhaps the most well-known member of the Cambridge Five, Philby was a high-ranking official in British intelligence, serving in MI6. He was exposed as a Soviet spy in 1963 and defected to the Soviet Union.
Burgess worked for MI6 and later the BBC. He defected to the Soviet Union in 1951, just before he was about to be exposed.
Maclean was a British diplomat and a member of the British Foreign Office. After carrying out espionage activities for the Soviet Union, he defected in 1951 along with Burgess.
Blunt was an art historian and a trusted member of British intelligence. His espionage activities were not publicly revealed until 1979. Blunt confessed to being a Soviet spy and was granted immunity from prosecution in exchange for his cooperation.
Cairncross served in various government positions, including at MI6. His espionage activities became known in the 1950s, but he was not publicly identified as a member of the Cambridge Five until later. Cairncross confessed in 1951 but was not prosecuted.