A man has been arrested after allegedly climbing over the front gates of Buckingham Palace while the Queen slept inside.
Police are said to have caught the intruder quickly after got into the grounds just off The Mall.
The Queen was in residence at the time, having returned from a visit to Cambridge.
A 22-year-old man was arrested on suspicion of trespass at 2am on Wednesday morning.
The alleged intruder was not armed and the incident is not being treated as terrorist related.
The man remains in custody at a south London police station.
The incident comes nearly 37 years to the day that intruder Michael Fagan broke into Buckingham Palace and entered the Queen's bedroom.