Recent declassified MI5 documents have shed light on the shocking revelation that Queen Elizabeth II was kept unaware of a significant spy within her royal household for nearly a decade. The files reveal that Anthony Blunt, a high-ranking courtier, was a Russian spy, and the Queen was not briefed on this betrayal for nine years following his confession. Additional documents have also disclosed insights into the notorious Cambridge Five spies, including Kim Philby, who admitted to his espionage activities but expressed regret over none of his actions. The files illustrate the profound implications of trust and secrecy within the royal palace, leaving the Queen in the dark while significant treachery unfolded in her inner circle.