Which real-life intruder is depicted in the episode 'Fagan' of The Crown?

The real-life intruder depicted in The Crown episode “Fagan” was Michael Fagan. In July 1982, Fagan broke into Buckingham Palace and reached Queen Elizabeth II’s private bedroom, an extraordinary security breach that became one of the most famous incidents of her reign.

The episode appears in season 4 and dramatizes Fagan’s two palace intrusions, including the later break-in that brought him face to face with the Queen. The series uses the event to explore public frustration and Britain’s social problems during the early 1980s, although some scenes are dramatized and dialogue cannot be treated as a literal transcript.

Fagan is sometimes confused with other famous intruders or political attackers, including Ian Ball, who attempted to abduct Princess Anne in 1974. John Hinckley Jr. and Mark David Chapman were American attackers associated with separate incidents involving Ronald Reagan and John Lennon.