Prince Harry‘s bombshell memoir Spare was published in 2023, with the Duke of Sussex penning many stories about his life with The Firm and his struggles as King Charles‘ second son.

According to several royal experts, Prince William was reportedly displeased with his father not sticking up for him after the book’s release.

“When it comes to Harry, William drew a line in the sand after the publication of Harry’s memoir, Spare, and he is disappointed that his father is not standing up for him,” royal author Christopher Andersen told Fox News recently.

“William loves his father and appreciates better than anyone how underestimated Charles has been over the years. He wants the king to leave his mark on history. But deep down, he knows he and his family — particularly his wife, Kate Middleton — are the future of the monarchy,” the writer noted.

Harry, 41, and his wife, Meghan Markle, left the royal family in 2020 and headed for California to start new lives away from the U.K. spotlight. The pair have been estranged from The Firm ever since then.

In Spare, the Invictus Games founder detailed a heated confrontation he had with William, 44, back in 2019 after the latter called Meghan, 44, “difficult” and “rude.”

Another anecdote in the book described the moment during the Duchess of Sussex’s wedding, when Kate, 44, reportedly made her cry over flower girl dresses.