A man was charged with intent to "alarm her Majesty" after being arrested at Queen Elizabeth's Windsor Castle home with a crossbow on Christmas Day last year, police and prosecutors said.
Jaswant Singh Chail, 20, a resident of Southampton in southern England, was arrested on the grounds of Windsor Castle, where the queen often resides. Chail was carrying a crossbow, prosecutors said.
At the time of the incident, the queen was at the castle, along with her son and heir Prince Charles, his wife and other close family members. According to police, Chail did not break into any buildings.
Following an investigation by counterterrorism police, Chail was charged with "discharging or aiming firearms, or throwing or using any offensive matter or weapon, with intent to injure or alarm her Majesty," an offense under section 2 of the Treason Act of 1842. He has also been charged with threats to kill and possession of an offensive weapon.
Nick Price, head of the CPS Special Crime and Counter Terrorism Division, said: "The Crown Prosecution Service reminds all concerned that criminal proceedings against Mr. Chail are active and that he has the right to a fair trial."
Chail will appear before London's Westminster Magistrates' Court on August 17.
Security breaches at the royal residences are rare. The most serious breach under Elizabeth's reign happened in 1982 when an intruder climbed a wall of Buckingham Palace, the queen's home, and made his way to her bedroom.
In 2003, Aaron Barschak, a man who called himself the "comedy terrorist," evaded security wearing a pink dress and an Osama bin Laden-styled beard to gatecrash the 21st birthday party of Charles' elder son, Prince William.
Some information for this report came from The Associated Press and Reuters.