The Moment Princess Kate Reportedly ‘Promised’ Prince William She ‘Was Done’ With Prince Harry

It’s long been reported that Prince William has been at odds with brother Prince Harry for years — and now Princess Kate is allegedly done with the Duke of Sussex as well.

In an excerpt from royal expert Christopher Andersen’s book Kate! The Courage, Grace, and Power of the Woman Who Will Be Queen (out Tuesday, May 5), the author claimed that Harry’s May 2025 interview with the BBC was the final straw for the Princess of Wales, 44.

When the Spare author, 41, said he didn’t know “how much longer” his father King Charles III had following his cancer diagnosis, the comment made Kate “more disappointed than angry,” Andersen wrote in the excerpt published by Us Weekly on Monday, May 4.

The interview, in which Harry spoke about his ongoing tension with the royal family, allegedly pushed Kate — who also revealed that she was diagnosed with cancer — to her “limits.”

According to Andersen, after Harry’s interview, Kate “promised” William that she “was done” with her brother-in-law.

“The damage was done: seeds of doubt concerning the King’s chances for a full recovery had been sown,” Andersen wrote.

“I think Kate’s relationship with her father-in-law over their shared cancer battles really has made her much more sensitive to King Charles’s feelings,” Andersen told Us Weekly. “She knows better than anyone that having someone publicly imply you may be at death’s door is horribly demoralizing.”

“I’m sure Kate must have felt stung by that comment as well, since she is in a situation very similar to the king’s,” Andersen added, explaining that he doesn’t see Harry and Kate “having any sort of relationship” going forward.

“At least not for the foreseeable future,” he speculated.

Harry and wife Meghan Markle stepped back from senior royal duties in 2020 and moved to California. For years, the Prince of Wales, 43, has seemingly been estranged from his brother.

According to Andersen, William “slammed the door shut on his brother over what Harry wrote in Spare.”

After the BBC interview, the author claimed in his book, “Now it was time to nail the door shut once and for all, and for the first time Kate, who had worked harder than anyone to mend the rift between the brothers, willingly handed her husband a hammer.”