Prince Harry says Princess Diana and Meghan Markle would be 'thick as thieves'

— -- Just hours after Prince Harry's engagement to Meghan Markle was announced, the royal reflected on what his late mother would think of his new fiancée.

In an interview with the BBC on Monday, Harry gushed that Princess Diana and the former "Suits" actress would be "thick as thieves, without question."

He also noted how much he would have loved to have been able to share the news of the engagement with her.

"I think she would be over the moon, jumping up and down, so excited for me. But then, as I said, [she] would've probably been best friends with Meghan," he told the BBC. "It is days like today when I really miss having her around and miss being able to share the happy news, but with the [engagement] ring and with everything else that's going on, I'm sure she's with us, jumping up and down somewhere else."

Prince Harry, 33, and Markle, 36, began dating a year and a half ago after they were set up on a blind date by a mutual friend, and were engaged earlier this month. Harry said that he popped the question over dinner at their home in London, and when she accepted, he presented her with a ring he designed himself, comprised of a diamond sourced from Botswana, a country with meaning to the couple, and two side stones from Diana's collection. Harry said he wanted to include his mother's diamonds "to make sure that she's with us on this crazy journey together."

"I think everything about Harry’s thoughtfulness and the inclusion of [Princess Diana’s stones] and obviously not being able to meet his mom, it’s so important to me to know that she’s a part of this with us,” Markle told the BBC. “It’s incredibly special to be able to have this [ring]."

Family is, of course, of great importance to both Harry and also Markle, who grew up in Los Angeles and recently moved to the U.K. to be with her future husband. While Harry asked for her parents' blessing before proposing, has spent time with her mother and spoken with her father, Markle has also had a chance to get to know his "welcoming" family on both sides, including Queen Elizabeth II, whom she called "an incredible woman."

"It's incredible I think, to be able to meet her through his lens, not just with the honor and respect he has for her as the monarch but the love that he has for her as his grandmother," Markle told the BBC. "All of those layers have been so important for me so that when I met her, I had such a deep understanding, and of course incredible respect, for being able to have that time with her."

"And the corgis took to her straight away!" added Harry with a smile.

Prince Charles, Prince William, and Duchess Catherine have also embraced Markle, Harry said. Introducing her to his family was "exciting," he said, and made just slightly simpler by the fact that they live close by.

"Catherine's been absolutely amazing," Harry said, and Markle agreed that she's been "wonderful." Harry also called his brother "a fantastic support."

"The family together have been absolutely a solid support, and my grandparents as well have been wonderful throughout this entire process. They've known for quite some time, so how they haven't told anybody is, again, a miracle in itself!" he told the BBC. "But the whole family have come together and have been a huge amount of support."

"They've been amazing," Markle added.