Princess Diana remains a beloved figure years after her untimely death.

Editor’s Note: Don’t miss CNN’s six-part documentary series “Diana” featuring rarely seen footage and new interviews that reveal the person behind the princess. “Diana” premieres Sunday, October 10 at 9 p.m. ET/PT.

CNN  — 

For centuries, the British monarchy has been known for its formal and rigid exterior. Members of the royal family have carried a stoic presence during public engagements, showcasing the institution’s affinity to a stiff-upper-lip attitude. But Diana, Princess of Wales, challenged royal norms and made the royal family more relatable.

Her rise to international stardom as a philanthropist and glamorous icon was heavily rooted in her approachable demeanor, kindness and rebellious spirit. In doing so, she made the royal family members more accessible. This influenced the way royals like Catherine, the Duchess of Cambridge, and Meghan, the Duchess of Sussex, interact with the public and the press today.

Here are five times Princess Diana broke royal protocol.

1. Diana omitted the word ‘obey’ from her wedding vows

Diana, Princess of Wales, with Prince Charles of Wales at their wedding at St Paul Cathedral in London in 1981.

It’s been a longstanding tradition for royal brides to say they will obey their husbands while reciting their wedding vows.

But when Diana, 20, married Prince Charles, 32, in 1981, she decided to remove the word “obey” from her vows – breaking royal precedent. Instead, Diana said she would “love him, comfort him, honor him, and keep him, in sickness and in health.”

The original phrase is from the 1662 Anglican Book of Common Prayer, which does not include the word “obey” in the husband’s vows toward his wife. Even Princess Elizabeth made her vows to obey her husband, something that would be technically impossible when she later became Queen.

Both Kate and Meghan followed in Diana’s footsteps omitting the word “obey” in their wedding vows decades later.

2. A royal education outside the palace walls

Prince Charles, Princess Diana and Prince William attend Prince Harry's first day at Mrs Mynors' nursery school in London in 1987.

Diana made history again when her eldest son, Prince William, was three and she decided to send him to preschool – making him the first member of the royal family to attend preschool outside of the Buckingham Palace. In the past, future heirs to the throne stayed at home with a governess.

In 1985, the Prince and Princess of Wales escorted their eldest son to his first day of school at Jane Mynor’s Nursery School in London, according to the New York Times. Princess Diana, who once worked as an assistant teacher, chose the small school because she wanted William to have a normal English child’s education, the NYT reported at the time.

Prince Harry eventually followed in his brother’s footsteps by attending the same school two years later. Diana’s choice to provide her sons with an early public education showcased not just her bravery to break from royal protocol but to expose her sons to as much a normal life as possible.

3. Debunking the stigma around HIV/AIDS

In 1987, Diana intentionally shook hands with an AIDS patient, working to dispel the myth that HIV/AIDS could be spread through touch.

One of the most iconic parts of Diana’s legacy was her involvement in the HIV/AIDs epidemic.

In 1987, Diana opened the UK’s first HIV/AIDs clinic in London, when the virus was becoming a global health crisis and was often associated with misinformation. It was at this clinic where Diana shook the hand of an AIDs patient – without gloves.

“HIV does not make people dangerous to know, so you can shake their hands and give them a hug, heaven knows, they need it,” Diana said in 1987.

At the time, it was controversial because many falsely believed the virus could be transferred through touch. This illustration of compassion and empathy for those affected by HIV/AIDs sent a clear message that if a royal family member wasn’t afraid to touch an AIDs patient than neither should anyone else. The scene was played around the world.

“The image of her holding hands with HIV/AIDS. … It shattered the stigma, prejudice and fear that surrounded HIV/AIDS in the early days,” said Andrew Parkis, chief executive of the Diana Princess of Wales Memorial Fund.

Four years later, first lady Barbara Bush joined Diana at the clinic visiting patients, proving the Princess of Wales had strong political influence across the pond.

Today her humanitarian work lives on. The Diana Princess of Wales Memorial Fund, set up after her death, has raised millions and distributes funds to dozens of causes supported by Diana, including AIDS prevention, the hospice movement and landmine clearance.

“The memorial has done a lot of good,” Diana’s brother, Charles, the ninth Earl Spencer, said. “She didn’t go for the soft option. She didn’t go for the conventional charitable ideas that appealed to other people. … She went for the messy ones, the complicated ones, the frightening ones and made them her own.”

4. Modern fashion choices

This is the evening gown worn by Britain's Princess Diana for the State Dinner at the White House in 1985, when Diana danced with John Travolta.

Princess Diana broke royal protocol in her fashion choices numerous times, opting for more modern and casual pieces.

One of the most celebrated moments for the fashion icon was when she donned a midnight blue velvet, off shoulder dress while dancing with John Travolta at the White House in 1985. Her elegance and grace made this photo unforgettable.

Another iconic look was her “revenge dress,” the asymmetric, figure-hugging mini dress she wore to a London event the day Prince Charles’ publicly admitted to having an affair in 1994. Black was considered only appropriate for royals during funerals.

“Her style was so very much her own,” said Jack L. Carlson, whose label Rowing Blazers recently launched a Diana-inspired clothing line. “She was not a follower. To the contrary, she did her own thing, and we all watched in wonder and tried to keep up.”

5. Raced barefoot at a school event

Diana runs barefoot as she takes part in the Mother's race during Prince Harry's school sports day on June 11, 1991.

This lighthearted moment captured at one of Prince Harry’s school events showcased yet again the Princess of Wales’ appetite for fun and competition. She was publicly a more hands-on parent than previous royal generations. She took her sons skiing, to the beach, to water parks and even car racing.

In 1991, Diana participated in a foot race with other parents for “sports day” at Wetherby School. She ran barefoot and lost the race, reported Harper’s Bazaar.

Royals are usually expected to keep their shoes on when in public. Most of these royal guidelines are learned and unspoken. According to Vogue, one these rules is that shoes must be kept clean and tidy.

But Diana didn’t let these guidelines infringe on her fun. Prince Harry said in an ITV/HBO documentary after Diana’s passing that she was a “kid through and through.”

CNN’s Megan C. Hills and Jack Guy contributed to this report.