It’s been 26 years since the world lost the "People’s Princess" – and all eyes are on the royal wives she never met.

Princess Diana, the glamorous mother of Princes William and Harry, died on Aug. 31, 1997, from injuries she sustained in a Paris car crash. She was 36. At the time, the ex-wife of the future King Charles III was being chased by paparazzi.

Years after enduring their mother’s tragic loss, the Prince of Wales and the Duke of Sussex married two different women from two unique upbringings. 

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A side-by-side photo of Meghan Markle, Princess Diana and Kate Middleton wearing red dresses

Meghan Markle, the Duchess of Sussex, and Kate Middleton, the Princess of Wales, have taken inspiration from their late mother-in-law Princess Diana over the years. (Getty Images)

William married Kate Middleton, the daughter of a flight attendant and a flight dispatcher, in 2011. In 2018, Harry tied the knot with Meghan Markle, a former American actress.

A composite photos of Princess Diana, Kate Middleton and Meghan Markle on their wedding day

Princess Diana, Kate Middleton and Meghan Markle kiss their prince. (Ben Stansall, Leon Neal/AFP via Getty Images)

As both women attempted to carve out their identities in the public eye, the wives have continually been compared to Diana, the former nursery schoolteacher who brought lasting change to the royals.

Princess Diana sitting on the steps of Highgrove House

Princess Diana was called "Shy Di" for her quiet demeanor. (Tim Graham Photo Library via Getty Images)

"I’m sure if a poll were taken today, Diana would easily rank as the most popular royal of all time," Christopher Andersen, author of "The King," told Fox News Digital. "Had Diana not entered the picture when she did, I can’t imagine that we would care half as much about the royal family. She breathed new life into what was becoming a musty and outdated monarchy, and continues to even today."

Princess Diana wearing the lovers knot tiara in a white dress looks off camera

Princess Diana passed away on Aug. 31, 1997. She was 36. (Terry Fincher/Princess Diana Archive)

"I think Diana would be thrilled that her sons fell in love with and married two dynamic and fascinating young women," he shared. "Kate is a no-brainer – she fulfills every wish Diana might have had for a daughter-in-law destined to become queen. I think Diana initially would have been happy with Meghan as well, identifying strongly with the divorced biracial American actress as a fellow outsider."

Princess Diana wearing her revenge dress

Princess Diana wearing her iconic "revenge dress." (Tim Graham Photo Library via Getty Images)

Diana, once called "Shy Di" for her quiet demeanor, transformed herself into a style icon during the ‘80s and ‘90s. She made her mark with couture, which consisted of Chanel suits, Versace evening gowns and Dior handbags. As the most-photographed woman in the world, the royal proved to be influential in both her humanitarian work and personal style.

Middleton, 41, and Markle, 42, have both worn jewelry pieces once owned by Diana and have even emulated her style while publicly supporting their causes.

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A side-by-side photo of Princess Diana and Kate Middleton on the day of their engagements

Kate Middleton's 12-carat oval sapphire engagement ring once belonged to Princess Diana. (Chris Jackson/Getty Images)

"It is well documented that Diana had a difficult time as the wife of our [now] king, but it was perhaps as a result of her suffering that she blossomed so fully, captivating everyone she encountered," royal fashion expert Miranda Holder told Fox News Digital. 

Side-by-side photos of Meghan Markle and Princess Diana wearing white suits and matching white hats

Meghan Markle, an American actress, became the Duchess of Sussex when she married Prince Harry, the younger son of the late Princess Diana, in 2018. (Getty Images)

"She may have been downtrodden in her marriage, but when it came to fashion, Diana was unafraid, ripping up the etiquette rule book and curating a catalog of fabulous and, at the time, groundbreaking outfits, each expressing sartorially what she could not verbally," she shared.

Princess Diana wearing her red and white black sheep sweater outdoors

Princess Diana wearing her "black sheep" sweater by Warm and Wonderful, circa 1981. (Tim Graham Photo Library via Getty Images)

"The results were dramatic, raw and unpredictable, and the effect was utterly compelling," Holder added.

A side-by-side photo of Kate Middleton and Princess Diana wearing polka dot dresses and hats

Like Princess Diana, Kate Middleton has used fashion to stand out "from the Windsor pack." (Getty Images)

But several royal experts agreed that there are warnings to be taken from Diana's brief life.

The Duke and Duchess of Sussex stepped back as senior royals in 2020. At the time, they cited what they saw as the media’s racist treatment of the duchess and a lack of support from the palace. They moved to the wealthy, coastal city of Montecito, California, that year.

In 2021, Markle told Oprah Winfrey in a televised interview that she felt constrained by palace life and that a member of the royal family even asked about the potential skin color of her first child before he was born.

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Oprah interviews Prince Harry, Meghan Markle

Oprah Winfrey interviewed Prince Harry and Meghan Markle for a special in 2021 where they revealed their struggles with royal life. (Harpo Productions/Joe Pugliese via Getty Images)

The couple went on to launch a six-part Netflix docuseries about their life together and Harry released his best-selling memoir, "Spare."

Diana had her own struggles with the palace, airing her grievances in a 1995 BBC interview that continues to make headlines. The network was forced to apologize in 2021 after an investigation found reporter Martin Bashir used "deceitful methods" to secure the tell-all.

During her televised sit-down, Diana said she was "bewildered" by critics who claimed she was "out to destroy the monarchy."

Princess Dianas Panorama interview

Martin Bashir interviews Princess Diana in Kensington Palace for the television program "Panorama." (© Pool Photograph/Corbis/Corbis via Getty Images)

"Why would I want to destroy something that is my children's future?" she said at the time. "I will fight for my children on any level in order for them to be happy and have peace of mind and carry out their duties."

Since the couple made their exit, the relationship between the two brothers has been strained. While promoting his memoir, Harry, 38, told Stephen Colbert that if his mother were alive, "we wouldn’t have got to this moment," adding, "There is no way that the distance between my brother and I would be the same."

Prince Harry Prince William mourn Queen Elizabeth

The relationship between Prince Harry and Prince William is said to be strained. (Aaron Chown/Getty Images)

"It’s hard to imagine that Diana would have approved of Megxit and the way it pitted her sons against each other," said Andersen. "Harry’s mother always wanted him to have a major role in supporting his brother, the future king. She would never have wanted Harry, no matter how upset his wife had become, to essentially turn his back on his birthright and the rest of the royal family."

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Meghan Markle and Prince Harry at an event

The Duke and Duchess of Sussex stepped back as senior royals in 2020. They now reside in California. It's been said that Princess Diana considered moving to California shortly before her death. (Getty Images)

Still, Andersen noted that Diana would "have sympathized" with the pressures the former "Suits" star faced after joining the royal family.

"Diana would have lent Meghan a shoulder to cry on," he said. "I think Diana could also have provided Meghan and Harry with valuable advice on how to cope."

True Royalty TV co-founder Nick Bullen told Fox News Digital that the most important lesson the wives could learn from Diana is simple – duty comes first.

A side-by-side photo of Megahn Markle and Princess Diana wearing lace hats

True Royalty TV co-founder Nick Bullen believes Meghan Markle could have handled her struggles with royal life differently. Similarly, Princess Diana felt like an outsider within the palace. (Getty Images)

Bullen is an award-winning documentarian who has been producing programs about the British royal family for 20 years. He has also worked closely with King Charles III, Harry's father, for about a decade. He noted that on his streaming platform, Diana continues to be the most popular royal among its subscribers.

"Even Diana at her darkest moments, when things were going very badly for her, she always believed in duty first and [having] a respect for the crown," Bullen explained. "Now there may have been issues between her and her husband, but she always respected the queen."

"Fergie is another great example of this," Bullen pointed out, referring to Sarah Ferguson, Duchess of York, who had a close bond with the late princess. 

"We’ve done a lot of work with Fergie," he said. "She always, and still now, talks about the lessons she learned from the late queen."

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Sarah Ferguson and Princess Diana laughing at each other during the Epsom Derby Match

Sarah, Duchess of York, and Diana, Princess of Wales, had a close relationship. (Georges De Keerle/Getty Images)

"Both she and Diana believed in duty and respect and loyalty to the crown," Bullen continued. "And I think Kate has done that fantastically. Kate knows she’s got a job to do, and that the job is to support the monarch… It's about supporting the monarch, supporting the crown and being loyal to that entity and understanding the job at hand."

"I’m afraid Meghan hasn’t shown that level of loyalty, respect or duty," he alleged. "And those are probably the things that Kate has learned from her mother-in-law."

But royal expert Richard Fitzwilliams pointed out that the women have carried Diana’s legacy in their own way.

A side-by-side photo of Kate Middleton and Princess Diana wearing red coats and black hats

Even during her early years dating Prince William, Kate Middleton, seen here in 2006, was compared to Princess Diana. (Getty Images)

"Whenever Catherine wears a jewel or an outfit as a tribute to Diana, it makes a statement, paying tribute to an icon," he said. "Likewise, when Meghan champions diversity and gender equality, these are areas where Diana would undoubtedly have been thrilled with the progress made since the 1990s."

"I think Catherine resembles Princess Diana when it comes to her passion for family, her passion for children and her fashion," chimed Kinsey Schofield, host of the "To Di For Daily" podcast.

"She has an ‘It’ factor," Schofield shared. "Catherine never engaged with paparazzi, which is very much a lesson that she would have learned from her mother-in-law, who did the opposite. I think we see Diana when Catherine is engaging with her babies in public – sweet, yet stern."

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Side-by-side phoot of Meghan Markle and Kate Middleton embracing children in the public eye

Just like Princess Diana, Meghan Markle and Kate Middleton aren't shy about interacting with children at royal engagements. (Getty Images)

"I think Diana taught Catherine that royal life is a marathon, not a sprint," she shared. "Kate’s patience and discipline is her not-so-secret weapon for thriving in the royal family. Both Diana and Catherine respect the monarchy and want to see it thrive for a King William reign."

"Princess Diana likely taught Catherine and Meghan to stay true to themselves, protect their peace and prioritize their families," Schofield added.

"Kate… is every bit as glamorous, stunning and stylish as her mother-in-law was," said Andersen. "Kate is no rebel, however, and that’s where Meghan comes in."

Kate Middleton wearing a polka dot dress and Meghan Markle wearing a blue and white striped shirt

Kate Middleton and Meghan Markle are seen here at the Wimbledon Tennis Championships on July 14, 2018, in London. (Karwai Tang/WireImage)

British royal commentator Jonathan Sacerdoti told Fox News Digital that one challenge both women will continue to face is stepping out of the shadow of their iconic mother-in-law.

Princess Diana wearing a powder blue suit while holding white flowers

During her brief life, Princess Diana made an unmistakable mark within the British royal family. (Tim Graham Photo Library via Getty Images)

"The legacy Princess Diana has left… is one of awareness," he explained. "Women who marry into the royal family know what they are marrying into, for good and for bad. They make that difficult choice knowing the life of privilege and luxury that they will lead, but also the possible difficulties and challenges that come with all that."

"You can look at her two sons’ wives to see two different ways that can go," Sacerdoti added.

The Associated Press contributed to this report.