A man was arrested in connection with an attempted break-in at Windsor Castle on Christmas Day.
Cops from Thames Valley Police (TVP) and the Metropolitan Police raced to the castle in Berkshire at around 8:30am.
Police were alerted to a security breach within the grounds of the castle - where the Queen is in residence.
A 19-year-old man from Southampton has been arrested following the incident.
The suspect is now being held in police custody.
The man did not manage to enter any buildings, Thames Valley Police confirmed.
The Royal Family has been informed of the incident and cops have launched a probe.
Superintendent Rebecca Mears, said in a statement: “An investigation is ongoing following this incident and we are working with colleagues from the Metropolitan police.
“The man has been arrested on suspicion of breach or trespass of a protected site and possession of an offensive weapon. He remains in custody at this time.
“We can confirm security processes were triggered within moments of the man entering the grounds and he did not enter any buildings.
“Members of the Royal Family have been informed about the incident.
“We do not believe there is a wider danger to the public.”
The Queen is spending Christmas Day at Windsor Castle and was expected to have lunch with the Prince of Wales and the Duchess of Cornwall, and the Earl and Countess of Wessex.
Charles, Camilla, Edward and Sophie, along with their children Lady Louise and James, Viscount Severn, attended a church service in St George's Chapel, in the castle grounds, at 10.45am on Christmas morning.
