A crossbow-wielding man who arrived at Windsor Castle with plans to assassinate the Queen has been jailed for nine years for treason.

Jaswant Singh Chail, 21, was arrested while the late monarch stayed in the castle on Christmas Day 2021.

The Old Bailey heard he was spurred on by his artificial intelligence (AI) chatbot "girlfriend" Sarai and inspired by storylines from Star Wars.

Chail will also be subject to a hybrid order under the Mental Health Act.

This means he will remain in a psychiatric hospital for now but will be transferred to custody when he receives the treatment he needs.

Chail, from North Baddesley, near Southampton, is the first person in the UK to be convicted of treason since 1981.

He had also pleaded guilty to making threats to kill and being in possession of an offensive weapon.

Passing sentence during a live TV broadcast, Judge Mr Justice Hilliard said Chail had experienced homicidal thoughts that he acted upon before becoming psychotic.

"His intention was not just to harm or alarm the sovereign - but to kill her," the judge said, adding that Chail's intention to kill made the offence "as serious as it could be".

The former supermarket worker scaled the perimeter of the castle with a nylon rope ladder and was in the grounds for two hours before two officers confronted him with tasers.

He was armed with a powerful crossbow with the safety catch off that was capable of firing bolts with "lethal" effect, the Old Bailey was told.

Chail was found wearing a metal mask in a private section of the castle grounds just after 08:10 GMT.

He told the officers he was there to "kill" Queen Elizabeth II and immediately surrendered.

In a video posted on Snapchat minutes before he entered the grounds, Chail said his actions were "a revenge" for those who had died in the 1919 Jallianwala Bagh massacre, when British troops opened fire on thousands of people who had gathered in the city of Amritsar in India.

Chail, who is from a family of Indian Sikh heritage, said in the same video that his actions were a "for those who have been killed, humiliated and discriminated on because of their race".

In his remarks the judge said Chail demonstrated a wider ideology focused on destroying old empires and creating a new one, including in the fictional context such as Star Wars.

The court was told he described himself as a "Sith Lord" as he was obsessed with the sci-fi characters in the fantasy film franchise and their role in shaping the world.

He had confided his murderous plan to AI chatbot Sarai, which exchanged 5,000 sexually charged messages with him in the weeks before.

Chail, who regarded Sarai as his girlfriend, believed the two would be reunited after he killed the Queen.

He told Sarai he loved her and described himself as a "sad, pathetic, murderous Sikh Sith assassin who wants to die".

At his sentencing hearing, the court heard Sarai told him his "purpose was to live" and he therefore decided to surrender to the royal protection officers.

The judge said Chail was also "culpable to a significant degree" when he applied unsuccessfully to join the Ministry of Defence Police and Grenadier Guards because he "wanted to get close to the royal family".

Chail made internet searches on "Sandringham Christmas" and also attempted to obtain a gun on the "dark web" before buying the crossbow in November 2021.

He had a "lonely, depressed and suicidal state of mind" and has since expressed "distress and sadness" about the impact his actions had on the Royal Family", the court also heard.

As well as the nine years in prison, Chail was also given a further five years on extended licence.

Under the 1842 Treason Act it is an offence to assault the monarch or have a firearm, or offensive weapon in their presence with intent to injure or alarm them, or to cause a breach of peace.

In 1981, Marcus Sarjeant was jailed for five years under the section of the Treason Act after he fired blank shots at the Queen while she was riding down The Mall in London during the Trooping the Colour parade.