In 1974, a violent scene played out on Buckingham Palace's doorstep, with a high-profile royal lucky to escape with her life.
It sounds like a storyline made for a television script – the attempted kidnapping of a member of the royal family that left three men bleeding on the roadside after trying to stop it.
In 1974, on March 20 about 8pm, it actually happened. Ian Ball – a 26-year-old unemployed labourer from north London – attempted to kidnap Queen Elizabeth's only daughter, Princess Anne.
The terrifying real-life event didn't make the cut in the new series of Netflix's The Crown, which covers the royal family from 1964 and 1977 but Erin Doherty's feisty take on Princess Anne has gained plenty of attention with some scene-stealing work.
Princess Anne and her then-husband Mark Phillips, a captain in the British army, were on their way home from a charity film screening when a white Ford Escort overtook their chauffeur on the mall, forcing him to stop about 200 yards away from Buckingham Palace.
A bearded man with light red hair jumped out of the Ford with two guns in hand and charged toward the rear of the royal limo.
Anne's bodyguard, Inspector James Beaton, stepped out to meet the man, assuming he was a disgruntled driver – only to be shot in the shoulder, and then twice more during the altercation.
Six more men faced off against Ball. Chauffeur Alexander Callender, one of the Queen's drivers, stepped out to confront the gunman and was shot in the chest.
Police constable Michael Hills, on patrol nearby when he heard the sounds of a struggle, was first on the scene. He approached Ball who shot him in the stomach. Before collapsing, Hills maintained enough strength to radio his station.
Company cleaning executive and former boxer Ronald Russell was on his way home from work when he saw the scene on the side of the road, approaching Ball on foot after seeing him shoot Hills.
Chauffeur Glenmore Martin parked his car in front of the white Ford to prevent Ball from escaping, while Daily Mail journalist Brian McConnell came onto the scene after recognising the limo's royal insignia and realising a member of the royal family was in danger.
Ball shot McConnell and he fell to the road: now a third man was bleeding onto the pavement.
But it was the Princess herself who ultimately kept Ball distracted from his goal.
"Please, come out," said Ball to Anne, grabbing her by the forearm as Phillip held onto her waist. "You've got to come."
As the two men struggled over the Princess, her dress ripped, splitting down her back.
Instead of panicking, she had what she later called "a very irritating conversation" with her potential kidnapper.
"We had a sort of discussion about where or where not we were going to go," Princess Anne said, recalling her exchange with Ball in an interview with Michael Parkinson in the 1980s.
"Well, he said I had to go with him – I can't remember why.
"I said I didn't think I wanted to go … And we had a fairly low-key discussion about the fact that I wasn't going to go anywhere, and wouldn't it be much better if he went away and we'd all forget about it."
After Ball shot McConnell, he turned back to his struggle for Anne when Russell approached him from behind and punched him in the back of the head.
While the former boxer distracted the gunman, Anne reached for the door handle. "I thought that if I was out of the car that he might move," she said – and she was right. As Ball ran around the car toward the Princess, she jumped back in and shut the door.
With more police officers now witnessing the action, Ball took off running and temporary detective constable Peter Edmonds – who'd heard Officer Hills' radio call – chased the kidnapper through St James Park, throwing his coat over Ball's head and tackling him to make an arrest.
"We are very thankful to be in one piece," Princess Anne said on the night of the ordeal.
"But we are deeply disturbed and concerned about those who got injured."
Attorney-General Samuel Silkin later told the extraordinary story of how, over two years, Ball planned the kidnapping of the Princess in minute detail.
He had intended to hold her ransom for £3 million ($A5.5 million) and to give the money to the NHS, in the hopes it would be used for the care and treatment of psychiatric patients.
Using the name John Williams, he purchased two guns in Spain, rented a house close to Princess Anne's residence in Sandhurst, and wrote a long ransom note to the Queen.
The papers reported that one line in the rambling letter read, "Anne will be shot dead."
In aiming to kidnap Anne, Ball was targeting the celebrity royal of the time, and while the media was told there would be an increase in royal protection, Buckingham Palace released a statement saying that the royal family "had no intention of living in bulletproof cages".
Chief among them was Anne, who valued her privacy even after recognising her fortune in escaping unscathed.
"There was only one man," she later said. "If there had been more than one it might been a different story."
When Ball appeared in court, he stated that his wish "to draw attention to the lack of facilities for treating mental illness under the National Health Service" was what motivated his crime. He pleaded guilty to attempted murder and kidnapping charges and was sentenced to a life term in a mental health facility.
That September, the Queen awarded the George Cross – Britain's highest civilian award for courage – to Inspector Beaton, who Anne said, "acted particularly bravely and, although already shot, he continued to protect us".
Police Constable Hills and Ronald Russell were both presented with the second-highest civilian honour of bravery, the George Medal.
In a 2006 interview, Russell recalled what the Queen said as she presented him with his medal: "The medal is from the Queen of England. The thank you is from Anne's mother."