David Huber threw shotgun cartridges through Buckingham Palace gates

But 60-year-old David Huber's attempt to get the attention of the royal couple backfired dramatically as his actions triggered a major security alert, and led to his immediate arrest, Carlisle Crown Court heard.

Police also carried out a controlled explosion on his rucksack.

But at the time, four days before the coronation of King Charles III, Huber was going through a severe “mental health episode” linked to an ongoing dispute over his dog breeding business in the Eden Valley.

His bizarre actions on May 2 last year triggered an immediate response from royal protection police officers and led to a controlled explosion of Huber’s rucksack, which he told police would not be dangerous provided it was not “mishandled.”

At an earlier hearing, the defendant, from North Stainmore, admitted six offences:

• Possessing lock-knife in a public place – outside Buckingham Palace - without lawful authority – on May 2.
• Possessing ammunition for a firearm without a certificate, with the charge stating that this happened in London on May 2 and the ammunition consisted of 12 ”.22 long rifle calibre cartridges.”
• A second illegal ammunition possession charge, relating to May 8, when the defendant possessed 244 rifle .22 long rifle calibre cartridges which the defendant had illegally in Cumbria.
• Illegally possessing on May 8 a prohibited weapon, a stun gun, capable of discharging an electrical charge.
• Possessing an offensive weapon in private place, a reference to a black acrylic, identified as a "police-style" tactical baton that the defendant had at his North Stainmore home in the Eden Valley. This charge related to May 18.
• And a further charge from May 18 of possessing 214 .22 rifle cartridges, again without holding a firearms certificate.

Prosecutor Gerard Rogerson outlined the facts.

He said Huber had originally been the holder of a firearms licence but police refused to renew it in 2014 because of concerns over his mental health. The defendant had been successfully running a dog breeding business at North Stainmore, near Kirkby Stephen.

But there had been a dispute with his business partner and as a result Huber’s mental health began to decline. He had been told the leave the farm.

Summarising the effect of the dispute, Huber told police that his business partner had "driven him to the bowels of hell."

One of his colleagues had spoken of how Huber recalled working on a shoot on land owned by the Duke of Westminster and how Prince William and Princess Kate took part.

Huber said he met the royal couple and, after the shoot, collected some of the spent cartridges they had fired, each bearing the Sandringham stamp.

On the day of the offences, a friend who gave him a lift to the railway station said Huber seemed agitated. The defendant told the man he had a hunting knife, which the man suggested he leave behind.

Huber agreed to do this, leaving the  knife with his friend.

Mr Rogerson described how the defendant arrived in London, initially looking for the “British Embassy”. He then made his way, via Kensington Palace, to Buckingham Palace, where he approached the main North Gate and threw over the two cartridges.

Though the cartridges were spent, Huger had inserted live bullets inside them before then resealing them, the court heard.  When police searched the defendant, they found he was carrying a lock-knife.

Huber later told the police that he wanted the police to talk to him and he threw the ammunition over the gate so he appeared to have “sinister intent.”

But he also said: “I adore the royal family; and I would take a bullet for them.”

Mr Rogerson then outlined how a search of the defendant’s home led to the discovery of more than 600 items of ammunition, as well as the police style baton and a stun gun device which was disguised to look like a torch.

When interviewed, he told police that he had sold dogs to Prince William and Princess Kate. “I thought I could speak to them and they could help me,” he said, adding that he was not in his right mind and had been diagnosed with bipolar in 2016

He believed the royals would relate to him and help him. Huber told the officers: “I’m disgusted that I did this, but I need to get my voice heard.”

In 2016, Huber believed his business was being targeted by criminals. “He said the police didn’t help and ridiculed and patronised him and treated him unfairly,” said Mr Rogerson.

Daniel Bramhall, defending, said Huber’s dog breeding business had become very successful and it was an enterprise he took pride in.

But after becoming involved with his business partner in 2018, he lost his life savings and the business was ruined, he said.

The ammunition found at his farm was legally acquired while the lock-knife was something he used to open bags of dog food.

The barrister said: “My primary submission is Mr Huber’s mental health, which has caused him significant difficulties. During his interview with the police, he said he was poorly and that is an understatement.

"His long battle with mental health started in 1999.”

He believed there was a conspiracy against him and that was why he went to London. “At the time his actions and explanations are indicative of indicative of someone who was acutely unwell,” said Mr Bramhall.

Judge Nicholas Barker noted how the defendant’s relationship with his business partner had soured and how this coincided with a significant decline in his mental health, and how he had kept the Sandringham shotgun cartridges for seven years.

“You were experiencing a mental health event,” said the judge, noting the defendant’s behaviour included elements of paranoia and delusion.

“I am convinced that that you would be better treated in the community rather than custody.” He imposed a two-year community order which includes a 12-month mental health treatment requirement and 20 rehabilitation activity days.

The defendant’s business achieved considerable success and he even had dogs entered in the prestigious Crufts dog show.