Palace staffers were so worried about the feud between the two brothers following Harry’s marriage to Meghan Markle that it was the hot topic of discussion at a summit in the spring of 2019.

According to the newly released read, “Finding Freedom: Harry, Meghan and the Making of a Modern Royal Family,” Harry distanced himself from William to protect his wife.

Their relationship is still frosty as William remains upset by the fallout over Megxit. “It’s not anger, it’s hurt,” a source said.

“We need to design a system to protect the monarchy full stop,” said one source at a palace retreat before Harry and Meghan moved from Kensington Palace to Windsor.

“The future of this monarchy relies solely on the four people currently in Kensington Palace. The public popularity only lies with them,” said the insider, issuing a battle cry. “When [Prince Charles] becomes king, the only way it lasts is if the four of them are not at war.”

As Harry and Meghan now spend their days working on their new charitable venture, Archewell, at home in California with their 1-year-old son Archie, a friend of Harry’s admitted it will take time to heal the family wounds.

The pair were set up by friends Misha Noonoo, a designer, and Markus Anderson, the book confirms for the first time. But when the former “Suits” actress came into the prince’s life, one senior royal referred to the American as “Harry’s showgirl,” while another told an aide that, “she comes with a lot of baggage.” One high ranking courtier was overheard telling a colleague, “There’s just something about her I don’t trust.”

William told his younger brother to take time to think over the romance with “this girl,” which “pissed off” Harry, who thought his big brother was being a “snob.”

Although William was thrilled to see his brother so happy — a rarity — the future king also wanted to make sure that Harry “wasn’t blindsided by lust,” a friend of both royals said. “These brothers have spent their whole lives with people trying to take advantage of them,” the friend added. “They’ve both developed a radar to detect that type of person.”

William didn’t know much about Meghan, and she expected him to “grill” her when they first met. Instead, her future in-law told her that he “was looking forward to meeting the girl who has put that silly grin on my brother’s face.”

Harry was aware of the gossip about his wife. “He’s extremely protective of Meghan. He understands that a lot of people are against them, and he will do everything he can to keep her safe and away from getting hurt — even if that means distancing himself from those people,” a close friend of his told authors Omid Scobie and Carolyn Durand.

So Harry began to block out his brother.

As for William’s wife Kate, she is “an extremely guarded person,” a friend told the book.

“The distance came from both directions. Harry spent less time going over to see the children, but the invites from William and Kate were the first to dry up,” a source said. “Kate did little to bridge the divide. She was fiercely loyal to her husband and his family.”