MI5 files reveal Queen Elizabeth II remained unaware of Soviet spy's presence in her palace for nearly a decade

Anthony Blunt, a former surveyor of the Queen's pictures, was a Soviet double agent who passed secret information to Russia's KGB spy agency. He had been under suspicion for years before confessing in 1964. According to declassified MI5 files, Blunt felt "profound relief" after unburdening himself. The files also reveal that the Queen was unaware of Blunt's security record in December 1971, despite him having confessed to being a Soviet double agent.