Following his graduation from Cambridge University and a visit to Vienna, where he married Soviet agent Litzi Friedmann, Kim Philby was recruited by an NKVD illegal, Otto Deutsch. On his recommendation his friend Guy Burgess agreed to become a spy, and Burgess then approached Anthony Blunt, a don at Trinity College, and Donald Maclean, who had graduated from Trinity Hall in October 1934. Maclean joined the Foreign Office in 1935 and continued to supply information to his Soviet contacts until he was obliged to escape to Moscow in May 1951. Meanwhile Burgess, who graduated from Trinity College in 1935 and the following year joined the BBC as a radio talk show producer, gravitated toward the Secret Intelligence Service.
Blunt acted as a “talent spotter” for the group and identified another Trinity College student, John Cairncross, as a potential member. Having excelled in both the Home and Foreign Civil Service examinations, Cairncross joined the Foreign Office in October 1936 and for a time shared an office in the Western Department with Maclean, unaware that he too had become a Soviet spy.
In 1940, having worked as a war correspondent in Spain and France for The Times, Philby joined the Special Operations Executive to train agents in propaganda techniques, having been suggested by Burgess, who was himself working for SIS’s Section D as an expert on broadcasting. In September 1941 Philby was transferred to the SIS, where he worked throughout the war as a signals intelligence analyst, studying the enemy’s organization in the Iberian Peninsula.
At the end of the war, Philby, having established himself as an intelligence professional, in 1946 was posted to the SIS station in Istanbul. Three years later he was sent to Washington, D.C., where he learned that Maclean had become the focus of an MI5 investigation, based on VENONA texts, into the leakage of classified documents from the British embassy in 1944. On his tip, Burgess conveyed a warning to Maclean, by then promoted to head of the Foreign Office’s American Department, and both men fled the country in May 1951.
Upon the disappearance of Burgess and Maclean, suspicion fell on Philby, who was interrogated and dismissed from the SIS in November 1951, and then onto Blunt. Blunt had joined the Intelligence Corps on the outbreak of war, and in 1940 had been recruited into MI5 but had gone back to academic life at the end of hostilities. Under suspicion following the defections of Burgess and Maclean, he eventually confessed, in return for an offer of immunity, in April 1964 to having spied for the Soviets since his recruitment by Burgess in 1935.
Blunt confirmed that he had recruited Cairncross, who had resigned from his post in the Ministry of Supply in 1951 when questioned about his prewar contacts with Burgess. Although on that occasion Cairncross had denied having passed classified information to Burgess from the Foreign Office, he had hemorrhaged secret documents to the Soviets when he was a junior diplomat, and later from the Cabinet Office and from Bletchley Park, where he had worked during the war as a linguist. In 1944 he had been assigned to the SIS,
and after the war had joined first the Treasury and then the Ministry of Supply.
Although popularly known as the “Cambridge Five,” only Burgess and Blunt had been recruited at the university, and not all of them had been aware of the full extent of the spy ring—Cairncross was unaware that either Kim Philby, whom he had encountered briefly in the SIS, or his colleague Maclean was also a Soviet spy.
When the evidence against Philby mounted, he was confronted in January 1963, and in return for immunity from prosecution, he supplied a bogus confession before vanishing from his home in Beirut, only to emerge years later in Moscow. While Philby, Maclean, and briefly, until his death in May 1963, Burgess maintained a miserable existence in Moscow, Blunt continued to live as an academic in London until his public exposure as a traitor in November 1979.