Jaswant Singh Chail, 21, admitted the offences at London’s Old Bailey after he was arrested wearing a hood, mask and gloves in the grounds of the castle to the west of London at about 8am on Christmas Day, 2021.

Elizabeth, who died in September last year, was at the castle on the day of the intrusion with her son and now King Charles and other close family members.

“Chail entered the protected areas within Windsor Castle after making threats to kill her late Majesty Queen Elizabeth II. Thankfully police officers intervened and nobody was hurt,” said Nick Price, Head of the Crown Prosecution Service’s Special Crime and Counter Terrorism Division.

“This was a serious incident, but fortunately a rare one.”

Chail had spent months planning the attack, prosecutors had said at an earlier court hearing. When he was approached by a protection officer, Chail said: “I am here to kill the queen.”

He appeared at today’s hearing at London’s Old Bailey court via videolink wearing a black jacket and spoke only to confirm his name and enter guilty pleas to the three charges of making threats to kill, possession of an offensive weapon, and an offence under the 1842 Treason Act.

Judge Jeremy Baker said he would sentence Chail on Mar 31, and the court ordered medical reports be prepared.

In 1981, Marcus Sarjaent was sentenced to five years’ imprisonment under the Treason Act after he pleaded guilty to firing blank shots at the Queen during the annual “Trooping the Colour” parade in central London.