Professor Anthony Blunt was a distinguished art historian, who was curator of the Queen's pictures from 1945 to 1978, and director of the Courtauld Institute of Art from 1947. Like his accomplices, he became a committed marxist while at Cambridge, and apparently remained so until his death. At Cambridge he was a member of The Apostles, a non-political "conversation society" which nonetheless appears to have numbered many marxists among its members.
He was recruited by the Russians in advance of the Second World War. He may have been recruited by Guy Burgess, or Burgess and he may have been recruited around the same time. At some point, Blunt took part in a student trip to Russia, during which he made a "side trip" which may have been his formal recruitment. At around the same time, he was recruited by British Military Intelligence, for whom he worked during the war. He passed information received in this capacity on to his Soviet handlers, and he may also have been involved in recruitment of suitable agents for Burgess, who was apparently the ringleader of the group.
After the war he returned to his career as an art historian, making occasional programmes for the BBC, and publishing works on Poussin, Borromini and other French and Italian artists. It is unclear of what value he could have been to the Russians during these years. In 1951, he may have assisted in the defection of Burgess and Donald MacLean to the Soviet Union. At the very least, he was one of the first people to have been informed of their disappearance, which may ultimately have led to his discovery.
He was knighted in 1956, although it appears that he may already have been under suspicion around this time, as it was known that he had been close to Burgess. A document in an FBI file dated March 16th 1956 draws a connection between a letter found in the British Embassy in Cairo, postmarked Louisville, Kentucky, 1951, and a lecture Blunt was scheduled to give in Louisville later that month (March 1956). The letter was supposedly a communication between Soviet agents in connection with the defection of Burgess and MacLean, and the suggestion was made that Blunt's visit to Louisville may thus be significant. The FBI apparently decided it was not worth investigating, as they had no information about the letter beyond a local newspaper article, nor had they any indication that Blunt was involved in espionage.
An earlier document in the same file (dated 1953), however, refers to an application by Blunt for a visa to visit the USA. Although this document is almost entirely censored, one of sections not blacked out indicates that interviewing Blunt in connection with the defections was being considered. There is no indication as to whether such an interview ever took place.
His discovery eventually came in 1964, when he confessed to his activities in exchange for immunity. This was granted, and the matter was not made public, allowing him to continue in his various positions. One might speculate on several reasons why such immunity was granted: perhaps he was able to furnish British Intelligence with information of great value, it may be that the scale of his own spying was not that considerable, or it may be the case that British Intelligence considered it too embarrassing to publicly admit that such a distinguished personage had been working for the Russians. In any case, he was only publicly exposed in 1979, with the publication of The Climate of Treason by Andrew Boyle. The imminent publication of this book led Margaret Thatcher to reveal his activities to Parliament. Public ignominy followed, including the loss of all of his positions and the revokation of his knighthood.
Blunt's fascinating story had been dramatised on television twice, in Blunt (1987), in which he was played by Ian Richardson, and A Question of Attribution (1991), written by Alan Bennett. More recently, the Irish writer John Banville fictionalised Blunt's life for his excellent novel The Untouchable (2000).