A royal photographer says he didn't think Prince Harry and Meghan Markle's marriage would last 3 years

• Kent Gavin photographed and had a close relationship with Princess Diana.
• He told Insider he didn't think Prince Harry and Meghan Markle's marriage would last three years.
• Gavin's prediction was based on Diana's rocky experience with the royal family.

A royal photographer who was close to Princess Diana said in an interview with Insider he didn't have high hopes for Prince Harry and Meghan Markle's marriage.

Kent Gavin was the Daily Mirror's royal photographer for years, and he spent much of his career documenting Diana's life.

The two developed a friendship as he documented events like her wedding, Prince William's christening, and her royal tours, and he got an intimate view of how life as a royal affected her.

With that perspective in mind, Gavin said he did not think Harry and Markle's relationship could withstand the pressures of royal life when they shared the news of their engagement in 2017.

"When it was announced that Harry was going to marry Meghan, I said to my colleagues and a few people, 'I don't give that marriage three years,'" Gavin said.

He added that he didn't think someone who was used to the world of Hollywood would be able to deal with the monarchy, and Chloe Savage, Markle's wedding-dress maker, echoed that sentiment to Insider's Anneta Konstantinides in January.

"I cannot see Hollywood, which is Meghan, a beautiful woman, a confident actress, putting up with the system, which even Diana couldn't cope with," Gavin said.

Gavin's prediction proved incorrect, as Markle and Harry celebrated their third wedding anniversary in May.

But in the couple's interview with Oprah Winfrey, Markle did say she was "naive" about what it meant to marry a royal before she and Harry said "I do."

"I didn't grow up knowing much about the royal family," Markle, who grew up in the US, said. "It wasn't something that was part of the conversation at home. It wasn't something we followed."

She said she did not understand that the royal life projected to the public would extend to the private moments of her life. For instance, Markle said she was surprised when Harry told her that she had to curtsy when she met the Queen at the Royal Lodge.

"I genuinely thought that was what happens outside," she told Winfrey. "I thought that was part of the fanfare. I didn't think that was what happens inside."

In the same interview, Markle told Winfrey that she discovered after she and Harry tied the knot that the royal family would not "protect" her from the British press, which consistently published racist and untrue reports about her.

"It was only once we were married, and everything started to really worsen, that I came to understand that not only was I not being protected but that they were willing to lie to protect other members of the family," Markle said. "They weren't willing to tell the truth to protect me and my husband."

She said that lack of protection contributed to a deterioration in her mental health, sharing that she had suicidal thoughts while she was pregnant with her son Archie.

When she asked a senior member of the royal institution for help, Markle said they refused because of how it would make the royal family look.

So the actress' negative experience as a royal didn't lead to the downfall of her marriage.

Instead, it caused Harry and Markle to step back as senior members of the royal family and create a new life for themselves outside the pressures of the monarchy.