In a new book by historian Robert Lacey, startling new allegations concerning the breakdown of Prince William and Prince Harry’s tight relationship have surfaced.

The royal biographer, who also serves as an official consultant on Netflix’s “The Crown,” has revised his book “Battle of Brothers: William and Harry – The Inside Story of a Family in Tumult” with additional chapters and information. He  addressed the royal family’s continuing problems in the original book, which was released in 2020.

According to Lacey, before Harry and Meghan Markle’s wedding in May 2018, the brothers had worked through their issues, but their relationship deteriorated by fall.

But it started way back. In 2019, British bestselling author Katie Nicholl said that after Harry announced his engagement to Meghan Markle in 2017, William became more concerned about his brother and his whirlwind relationship with the American actress.

According to Lacey, William learned about the bullying allegations against Meghan from a top royal staffer before to their wedding in 2018. When William confronted Harry about it, they had a “fierce and bitter” argument.

“William threw Harry out,” a buddy said.

Lacey’s book recounts an enraged exchange between the princes, first over the phone and later in person, when William confronted Harry about the bullying allegations.

“When Harry flared up in furious defense of his wife, the elder brother persisted,” Lacey writes. “Harry shut off his phone angrily, so William went to speak to him personally. The prince was horrified by what he had just been told about Meghan’s alleged behavior, and he wanted to hear what Harry had to say. The showdown between the brothers was fierce and bitter.”

When the accusations of bullying initially surfaced in the UK newspaper The Times in March, the Duchess of Sussex’s staff vehemently denied them. The Palace established an independent probe examining the allegations and how they were handled.

“The Duchess is saddened by this latest attack on her character, particularly as someone who has been the target of bullying herself and is deeply committed to supporting those who have experienced pain and trauma,” the Duke and Duchess of Sussex said in a statement to Fox News on Wednesday.

“She is determined to continue her work building compassion around the world and will keep striving to set an example for doing what is right and doing what is good,” the statement said.

Lacey also said that William’s wife, Kate Middleton, was “wary of Meghan from the start.” He further alleged that William informed a buddy that he believed the former “Suits” actor had a “agenda” and that the allegations he was hearing backed up that notion.

A Kensington Palace employee said that “people felt run over” by Meghan and “didn’t know how to handle” her, Lacey claims.

In his and Meghan’s shocking appearance with Oprah in March, Harry discussed his current relationship with his brother and father, saying he was “trapped”

“I was trapped, but I didn’t know I was trapped,” he said of the time before he and Meghan stood down as senior royals.

William reportedly told a friend that he felt “hurt” and “betrayed” since he has always believed it was his responsibility to protect his younger brother. However, the British monarchy — and everything that it represents – came first.

The new extracts came as the brothers prepared to meet on July 1 to dedicate a monument honoring their late mother, Princess Diana, on what would have been her 60th birthday.

The brothers had last seen each other in April, during their grandpa, Prince Philip’s, burial.