Prince Philip warned Prince Harry about marrying Meghan Markle: report

Prince Philip reportedly advised his grandson, Prince Harry, against marrying Meghan Markle.

The Sunday Times reports that the Duke of Edinburgh warned his grandson before he proposed to his future wife back in 2017 that "one steps out with an actress, one doesn't marry them."

The claim that Philip expressed his doubts to Harry about the woman that he was gearing up to spend the rest of his life with comes six months after reports surfaced that his brother, Prince William, also shared his reservations with Harry about how quickly he had been moving with the former "Suits" actress.

SEE ALSO: Prince William expressed his doubts about Meghan Markle to Prince Harry

Reports claimed in December that things boiled over between the Cambridges and the Sussexes because Kate and Will thought that things had progressed between Harry and Meghan too swiftly: They married six months after he proposed, and he proposed about one year after they started dating.

"The problem is that the Cambridges felt things had moved very quickly between Harry and Meghan," a source told the Daily Mail at the time. "Wills particularly was worried and felt close enough to Harry to voice his thoughts."

While the royals reportedly cleared the air over the holidays, experts say that it took a while for Harry and William in particular to truly mend their bond, which "absolutely" resulted in a fallout.

"It's absolutely the case that the brothers did fall out," royals expert Katie Nicholl told ET. "I was told by a very senior royal source that actually they weren't talking to each other at one point."

SEE ALSO: Meghan Markle and Kate Middleton make telling move amid reports of tension

However, the May arrival of royal baby Archie Harrison appears to have been the mending force that perhaps Harry and William needed to rebuild their tight relationship as brothers.

"I certainly think now that Archie is here, it has probably really helped to improve the relationship," Nicholl added. "William is over-the-moon that his brother is a dad."

Prince Philip, 97, has kept a low-profile since retiring from public duty, but occasionally steps out for big occasions, most recently to meet his great-grandson, Archie.