Royal watchers had long hoped that Meghan Markle and Kate Middleton would band together as wives – but the women were never friends.

"There wasn’t really any relationship between the two of them," True Royalty TV co-founder Nick Bullen told Fox News Digital. "It was the brothers – Prince William and Prince Harry – who were falling out, not the sisters-in-law, not the wives."

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 the king for about a decade.

Kate Middleton wearing a white printed dress next to Meghan Markle wearing a blue and white striped blouse holding a wide brimmed hat

True Royalty TV's Nick Bullen told Fox News Digital that the world was rooting for Kate Middleton and Meghan Markle to form a tight bond behind palace doors. That never happened, he said. (Karwai Tang/WireImage)

On April 21, the streaming platform premiered "His Majesty’s Coronation: Behind the Throne," a special featuring a panel of royal experts and insiders who dug deep into the traditions associated with the coronation. King Charles will be crowned on May 6 at London’s Westminster Abbey.

Bullen said that despite the women putting on a brave face for the public, it was difficult for them to develop any kind of bond behind palace doors.

"I was talking to someone very early on in the Sussex marriage who had been at a dinner with Kate and had been asking about Meghan," Bullen claimed. "And Kate just said, ‘She’s just really different [from] the rest of us.’ And not in a negative way. They just didn’t have lots in common."

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A close-up of Kate Middleton smiling wearing a black turleneck

A source claimed that Kate Middleton found Meghan Markle "different from the rest of us," which made it difficult for the women to connect as royal wives. (Tim P. Whitby/Getty Images)

"Kate is sort of a well-to-do English girl who hadn’t really had many jobs and had married her prince," he explained. "Whereas Meghan was a divorced career woman from LA. They’re just different. So I think the relationship… was never really there as we, as the world, were hoping. We hoped it would be those shots of them going to Wimbledon together… [But] you’d be hard [pressed] to find moments when it was just the two of them coming together."

Bullen added the little relationship the wives developed "had broken down long before the death of the queen."

The Duke and Duchess of Sussex announced they were stepping back as senior royals in 2020.

Kate Middleton wearing a green dress next to Meghan Markle wearing a white blouse and sunglasses

The Princess of Wales and the Duchess of Sussex made few outings together without their husbands. (Karwai Tang/Getty Images)

"I think after the death of the queen, there wasn’t really a relationship to break down," said Bullen. "I don’t think it was there in the first place."

In the 2020 book "Finding Freedom," Omid Scobie and Carolyn Durand also revealed that the women never became close during Markle’s time living in the U.K.

"Meghan would agree with the assessment that the duchesses were not the best of friends," the reporters wrote. "Their relationship hadn’t progressed much since she was Harry’s girlfriend."

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A close-up of Meghan Markle smiling wearing a black top and a black necklace

Meghan Markle, an American actress, became the Duchess of Sussex when she married Prince Harry in 2018. (Samir Hussein/WireImage)

According to the reporters, the wives weren’t feuding because they didn’t know each other that well to begin with. They also noted that the Princess of Wales, in particular, never made a deep effort to become close to her sister-in-law.

Markle, a former American actress, envisioned that Middleton would offer a helping hand to help her understand "everything an outsider to the Firm needed to know." However, that never happened.

"Meghan was disappointed that she and Kate hadn’t bonded over the position they shared, but she wasn’t losing sleep over it," the reporters wrote.

A side photo of Meghan Markle wearing a dark hued dress next to Kate Middleton wearing a blue dress

The royal wives allegedly became more distant after the Duke and Duchess of Sussex moved to Frogmore Cottage in 2019. Prince Harry and Meghan Markle announced they were stepping back as senior royals the following year. (Chris Jackson - WPA Pool/Getty Images)

One source claimed in the book that Middleton didn’t feel they had much in common "other than the fact that they lived at Kensington Palace." That changed when the Duke and Duchess of Sussex moved to Frogmore Cottage in 2019, a year before their royal exit.

"Meghan would far rather have had Kate check in on her during the most difficult time with the press," Scobie and Durand wrote.

During her sit-down with Oprah Winfrey in 2021, Markle, 41, addressed reports that she left Middleton, 41, in tears leading up to her 2018 royal wedding due to a disagreement over bridesmaid dresses.

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Meghan Markle being interviewed by Oprah Winfrey

The Duke and Duchess of Sussex sat down with Oprah Winfrey for a televised interview in 2021. (AP)

"The reversed happened," said the former "Suits" star.

"And I don’t say that to be disparaging to anyone, because it was a really hard week of the wedding, and she was upset about something," Markle continued. "But she owned it, and she apologized, and she brought me flowers and a note apologizing. I actually think it’s – I don’t think it’s fair to her to get into the details of that because she apologized. And I’ve forgiven her."

Markle described Middleton as "a good person" and said people shouldn’t pit them against each other.

Kate Middleton wearing a light blue dress next to Meghan Markle wearing a pink dress

Meghan Markle described how U.K. tabloids pitted the royal wives against each other. (Max Mumby/Indigo/Getty Images)

"If you love me, you don’t have to hate her," said Markle. "And if you love her, you don’t have to hate me."

A source recently told People magazine that it was Middleton who came up with the idea to step out with the Duke and Duchess of Sussex following the queen’s death in September. The insider alleged it was meant to be a first step in reconciliation between the brothers and their wives, one that proved to be difficult for everyone involved.

At the time, Harry and Markle were in Europe for a series of charity appearances. Their two children, Prince Archie and Princess Lilibet, remained in California where they reside. It was around this time that the queen passed away at Scotland's Balmoral Castle at the age of 96. The couple extended their trip to attend the funeral.

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Prince Harry Meghan Markle Prince William Kate Middleton

Meghan Markle and Prince Harry held hands while walking at Windsor Castle with Prince William and Kate Middleton to view flowers and tributes to Queen Elizabeth II. (Chris Jackson)

According to the outlet, William invited his brother and sister-in-law to join him and his wife to greet mourners gathered outside Windsor Castle. A source insisted that the outing, meant to signify a united front, was Middleton's idea.

"She didn’t want her or William to have any regrets," a friend of the Princess of Wales told the outlet.

Earlier this month, Buckingham Palace confirmed that Harry will attend his father’s coronation solo. Markle will stay behind in California with the couple’s two children.

Prince Harry and Meghan Markle look serious in a photo

Buckingham Palace recently confirmed that Prince Harry will attend his father's coronation in May. Meghan Markle will stay behind in California with their two children, Prince Archie and Princess Lilibet. (Getty Images)

Harry and Markle, who is biracial, have alleged she faced racist attitudes from both the palace and the U.K. press. The treatment contributed to their decision to leave the country. The family now resides in the wealthy, coastal city of Montecito.

Back in 2018, Bullen told Fox News Digital that the royal wives were never at war.

"Let’s have these two super glamorous women – one British, one American. One an actress, one sort of an English rose. Let’s put them against each other," he explained at the time, adding "that’s the sexy sort of media story."

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Kate Middleton split Meghan Markle

In 2018, True Royalty TV's Nick Bullen told Fox News Digital that Kate Middleton and Meghan Markle weren't feuding. However, Prince William and Prince Harry's relationship was becoming strained. (Samir Hussein)

However, Bullen noted that the truth was "somewhat different."

"It’s actually that William and Harry have had a rift," he said. "I think you know, look. All brothers fall out. All families fall out. Their fallout at the moment is becoming public. I think people don’t want to think about that with these two boys. These are two boys who lost their mother [Princess Diana] at a really early age, and the fairy tale is that they are closer than ever, and need each other, and I think that’s probably true. But equally, they are two grown men in their 30s, starting their own families, different wives, they are moving to different parts of the country, different duties."

"I think it was sad," Bullen admitted. "You don’t want to hear this, but again, it goes back to them being real people. We forget that they are people."

Fox News Digital's Mariah Haas and The Associated Press contributed to this report.