Prince William allegedly "lunged" at Prince Harry twice and grabbed his shirt after Prince Philip's funeral, according to the Duke's memoir.
In a newly leaked passage, he claims that the incident took place as he held peace talks with his brother and father, King Charles, at Frogmore Cottage in April 2021.
Harry said that William told him “I just want you to be happy”, before the clash.
But detailing his response, the duke wrote: “My voice broke as I told him softly, ‘I really don’t think you do’.”
In the extract, obtained by The Sun, he described William as "really steaming" and claimed that he shouted: “You never came to us. You never came to me.”
Harry said that the men had all taken a half-hour walk before arriving at a gothic ruin near Frogmore Cottage.
He revealed that they discussed the Sussex's controversial Oprah Winfrey interview, which had taken place weeks earlier, and that he told them he felt they had "violated" their Megxit agreement.
Harry said that he had also attempted to address the bullying accusations against his wife.
But he claimed the conversation got heated and turned physical.
He wrote: "I waved a hand, disgusted, but he lunged, grabbed my shirt. ‘Listen to me, Harold’.
“I pulled away, refused to meet his gaze. He forced me to look into his eyes. Listen to me, Harold, listen! I love you, Harold! I want you to be happy."
Harry also said that William used a "secret code" about their late mother, Princess Diana, during the argument.
He claims that William told him: “Harold, you must listen to me! I just want you to be happy, Harold. I swear I swear on Mummy’s life."
It's the second physical altercation that Harry has alleged occurred between him and his brother in his memoir.
In another segment of the book, he claimed that William grabbed him by the collar and knocked him to the floor.
He alleged that they got into an argument when the Prince of Wales called Meghan “difficult”, “rude” and “abrasive”.
