The files about royal art historian Anthony Blunt are among a trove from the intelligence agency MI5 released Tuesday by Britain’s National Archives.

The identity of a Russian spy among Queen Elizabeth II's courtiers was kept from the monarch for almost a decade, but she took the news with her typically calm demeanour

Queen Elizabeth II was not told officially for nearly a decade that one of her most senior courtiers had admitted he was a Soviet spy, newly declassified British files revealed

Anthony Blunt, who worked at Buckingham Palace as Surveyor of the Queen’s Pictures, was secretly a Soviet spy during WWII.

Sir Anthony Blunt, the surveyor of the Queen's pictures, confessed in 1964 that he had been a Russian agent since the 1930s, when he was recruited into the Cambridge spy ring

Queen Elizabeth II was not officially informed for nearly a decade that Anthony Blunt was a Soviet spy, newly declassified documents reveal.

Documents newly declassified by MI5, Britain's internal intelligence agency, show the late Queen Elizabeth II was not informed for almost 10 years that a member of her staff had spied for the then-Soviet Union.

Newly declassified files reveal the late Queen's very unexpected reaction to the art historian's shocking secret.

For a decade, Queen Elizabeth II lived without knowing that her own art advisor, Anthony Blunt, a trusted man in charge of overseeing the invaluable Royal Collection, was living a double life as a Soviet agent.