Princess Diana famously broke new ground in the way royals performed their duties, paving the way for others to tackle causes close to their hearts.
From her down-to-earth approach during public walkabouts to wearing daring outfits not seen on other royal women, Diana was determined to do things differently in the House of Windsor.
But it was the late 1980s when Diana did something no-one had dared to ever attempt, shocking not only the royal family but the world.
The decade was dominated by a fear of HIV/AIDs due to a lack of understanding and misinformation.
It was an issue many high-profile people ignored because of the stigma attached to the disease, which disproportionately affected gay men.
The media called it “the gay plague”, just one of many derogatory terms linked to HIV/AIDs.
But it was a single gesture by Princess Diana that led to a dramatic shift in the way the world perceived patients and the disease.
On April 9, 1987, Diana opened the UK’s first purpose-built HIV/Aids unit, which exclusively cared for patients infected with the virus, at London Middlesex Hospital.
Without gloves and in front of the world’s media, Princess Diana shook the hand of a man suffering with the illness.
It was a move that publicly challenged the notion IV/Aids was passed from person to person by touch.
Instead, Diana believed the condition was one that needed compassion and understanding, not fear and ignorance.
“When Diana opened Broderip Ward, it was really an iconic event,” former nurse David Evans told the new documentary Diana’s Decades.
“The way AIDs was handled by the media, and by governments, had a lot to do with blaming – stigma and blame – so just to see a royal go and do this was totally amazing.”
One of the patients who shook Diana’s hand that day told the news cameras: “I think the princess actually helped to get the message across by the mere fact that she wasn’t wearing gloves”.
Two years later, Diana visited St Mary’s Hospital in Paddington where Evans worked on the HIV ward.
“On the day that Diana came to officially open the ward it was the first of December, World AIDs Day, and that was the first time I met her,” he said.
“I sometimes find it still a bit too upsetting to say this, but she was sitting next to a man with KS [kaposi sarcoma, or lesions] on his legs and you could see their knees were touching.
“So, all the fears, all the stigmas, around HIV she broke those barriers down just by having knee to knee contact.
“When Diana came over and shook my hand, I had tears streaming [down] and I said, ‘Oh Your Royal Highness you really made it for us’ cause she had.”
But Diana would go further during her first solo visit to America in 1989.
It was widely seen as her most controversial engagement yet – a visit to an AIDs ward for children in Harlem, in New York City.
Diana requested television crews and photographers be banned from covering her visit inside the ward. Just staff at the hospital were permitted to take photos of her while there.
“When she picked up those AIDs babies, she broke all the protocol, all the rules,” Ken Gavin, former chief photographer for The Mirror, told the documentary.
He had flown to New York to cover Diana’s three-day visit.
“The effect in the hospital with the nurses, the other people who were there, was just euphoria,” he said.
“They were amazed and couldn’t believe that a member of the royal family had done this.”
Staff told the princess they were surprised she had come to Harlem Hospital, a place never visited by any American president and few major political leaders.
The visit would cement Diana’s reputation as a humanitarian on the world’s stage.
Gavin was on the same plane as Diana as they flew back to London and spoke to her about the ground-breaking moment at Harlem Hospital.
“I said, ‘do you realise ma’am what you’ve done here? Nancy Reagan wouldn’t be doing that’ and she said, ‘I just felt emotion, I felt like crying’.
“But this is just how she was.”
In 1991, Diana told the Children and AIDS Conference in 1991 that people should give handshakes and hugs to those with the disease.
“Heaven knows they need it,” she said. “What’s more, you can share their homes, their workplaces, their playgrounds, and their toys.
“AIDS is the last straw in an already heavy burden of discrimination and misfortune.”
She later visited an orphanage for abandoned children in Sao Paulo, Brazil, which cared for babies and children who were HIV-positive or sick with AIDS.
The visit would provide some of the most iconic images of Diana, as she proved to the world there was no reason not to touch those who needed human contact more than anything.