The Cambridge Four

This title refers to a ring of Soviet spies based in the UK who passed information to the Soviet Union during World War II and into the early 1950's. They were originally known as the Cambridge Spy ring as all the known members of this ring were recruited whilst students at Trinity College, Cambridge.

Four men have been identified as belonging to this ring - Kim Philby, Donald Maclean, Guy Burgess and Anthony Blunt. It has been suggested but never proven that John Cairncross was also part of this spy ring.

'Kim' ( Harold Adrian Russell) Phiby

Cryptonym: Stanley

Whilst a student at Cambridge in the late 1920's, Philby became involved in the Communist movement. He joined the Comintern underground in Vienna, Austria and on the strength of his work for this organisation was recruited by the Soviet Intelligence agency.

By the 1940's Philby was back in the UK. Guy Burgess introduced him to Marjorie Maxse and SIS (later MI6) officer who recruited Philby as a British Intelligence Officer. Philby worked hard and paid great attention to detail. In 1944 he was appointed head of Section IX - counter espionage - against the Soviet Union. Quite and achievement for a Soviet spy.

After the war Philby was sent to Istanbul as Head of Station under the cover of First Secretary to the British Embassy. In 1949 he was assigned to the British embassy in Washington where he acted as a liaison between the embassy and the newly formed CIA.

After that things began to unravel. The cryptonym - Homer- who was Donald Maclean appeared in the Venona decrypts. Both Maclean and Burgess came under suspicion and so did Philby by association.

After the defection of Burgess and Maclean to Russia, Philby was asked to resign from the SIS. For the next few years he was questioned by MI5 and SIS but nothing was ever proved and so he was cleared of being the 'third man' by the then Foreign Secretary Harold Macmillan who made this statement in the House of Commons.

"While in government service he (Philby) carried out his duties ably and conscientiously, and I have no reason to conclude that Mr Philby has at any time betrayed the interests of his country, or to identify him with the so-called 'Third Man', if indeed there was one."

Philby was always in danger of having his cover blown by the next soviet defector, so in 1963 when confronted by new evidence he defected to the Soviet Union.

Donald Duart Maclean

Cryptonym: Homer

Maclean arrived at Trinity Hall, Cambridge in 1931 to study modern languages. Whilst there he joined the Communist party and in his last year was recruited into Soviet Intelligence by Anthony Blunt.

In 1934, Maclean started work at the Foreign Office in London. Whilst there he was under the operational control of Anatoli Gorsky. He was later psoted to the British embassy in Paris and was here when war broke out. He managed to get back to England aboard a royal Navy warship.

Maclean continued to report to Moscow from London. In September 1941, he told the Russians about the project 'Tube Alloys' - the building of a uranium bomb. He sent Moscow a sixty page report with the official minutes of the British Cabinet meeting where this project was discussed.

From 1944 to 1948 Maclean served as the Secretary to the British Embassy in Washington and the Secretary of the Combined Policy committee on Atomic Development. The information he provided enabled to Soviet scientists to predict the number of bombs that could be built by the Americans. Stalin knew that the USA did not possess an adequate stock of atomic weapons and this knowledge played a crucial role in Stalin's decision to institute a blockade of Berlin in 1948.

Maclean was also able to report to Moscow about the aims of the Marshall plan. His message revealed that the plan was to ensure American economic domination in Europe and to be a substitute for the payment of war reparations by Germany. This was unacceptable to the Russians as at that time, as war reparations were their sole source of foreign capital.

In 1949, Robert Lamphere, a FBI agents discovered that between 1944 and 1946 a member of the British Embassy staff was sending messages to the KGB. The code name was Homer, and by a process of elimination a short list of three or four individuals was drawn up. One of the names was Donald Maclean.

Shortly after this investigation Philby arrived in Washington and became aware of this development. Philby knew that if Maclean was identified as a Soviet agent and he were to confess, the trail might lead to the other members of the Cambridge Four.

Philby and Burgess put together a plan whereby Burgess would visit Maclean in London, make him aware of the situation and arrange for his defection to Russia. However, the KGB demanded that Burgess accompany Maclean behind the Iron Curtain rather than Maclean journey alone which was the option Philby preferred.

Meanwhile MI5 and the FBI decided to confront Maclean on Monday 28 May 1951.

However the Friday before, which was Macleans 38th birthday he defected to Russia with Burgess.

It is unclear why the Soviets were so determined that Burgess defected at the same time as Maclean. Perhaps they didn't trust him anymore, perhaps they felt he would be left very vulnerable, perhaps they thought he may reveal to the West who were his fellow agents.

Guy Burgess

Cryptonym: Hicks

Whilst a student at Cambridge Burgess became involved with Communism, and was ultimately recruited to be a Soviet agent.

His most useful role, as far as the Russians were concerned, was as secretary to the British Deputy Foreign Minister- Hector McNeil. Burgess was able to transmit top secret Foreign Office documents to the KGB on a regular basis.

When he was assigned to the British Embassy in America, Burgess continued to be a heavy drinker and indiscreet homosexual. His life style became a liability and he defected to Russia with Maclean in 1951.

Anthony Blunt

Cryptonym: Johnson

Recruited into the communist party whilst at Cambridge, Blunt was recruited into the NKVD ( the forerunner of the KGB) in 1934 following a visit to Russia. Blunt was a committed Marxist and instrumental in recruiting Guy Burgess and Donald Maclean as Soviet agents.

He joined the British Army in 1939 and was recruited into MI5 in 1940. He passed on information from decrypted Enigma messages to the Soviet Union.

After the war he became director of the Courtauld Institute of Art until 1974. he was also the Surveyor of the Kings' Pictures and was knighted as a KCVO for his work in 1956. In 1965 was the Slade Professor of Fine Art at Cambridge.

In 1963 Blunt recruited and American Michael Straight who informed MI5 of his espionage. Blunt confessed to MI5 in mid 1964 but his spying activities remained an official secret until 1979 when he was publicly named by Prime Minister Margaret Thatcher. He was stripped of his knighthood and removed as an Honorary Fellow of Trinity College.