Prince William Will 'Likely' Blame Prince Harry for Kate Middleton and King Charles' Cancer Diagnoses, Royal Biographer Warns

Prince William reportedly holds lingering resentment toward Prince Harry and even “likely” holds him responsible for Kate Middleton and King Charles’ cancer diagnosis, a royal biographer claims.

“There are arguments that some of these illnesses are being brought on by the problems of the so-called ‘spares,’” author Andrew Lownie told a news outlet in an interview published on Thursday, December 4.

Lownie, who has written multiple books about the royal family, explained that William, 43, “likely” blames his younger brother, 41, for the health issues that have struck the monarchy.

“I do think there will be a real crisis if something happens to Kate and she’s incapacitated,” the author continued. “She is the linchpin on which the whole future of the monarchy depends.”

Charles and Kate’s cancer diagnoses came just weeks apart, with Charles sharing his news in February 2024 and Kate, 43, revealing hers the following month.

Despite Harry’s estranged relationship with the monarch after he and his wife, Meghan Markle, left the royal family in 2020, the Spare author immediately flew to the U.K. after receiving the news of his father’s illness.

"I jumped on a plane and went to go see him as soon as I could," Harry told Good Morning America at the time. "Look, I love my family. The fact that I was able to get on a plane and go and see him and spend any time with him, I’m grateful for that."

While Harry and Kate – who announced she was in remission in January – still haven’t reunited publicly, the prince quietly reconnected with his father again last month. It was their first face-to-face meeting in more than 18 months and the “secret sit-down” allegedly left William “stunned,” with sources claiming he would’ve blocked it if he’d known sooner.

"William thought his father was back in London strictly for cancer treatment and official audiences. He had no idea Harry was on the schedule — and certainly wasn’t asked for input,” read Rob Shuter's Substack report at the time. “If William had been consulted, he would have tried to block it. That’s why Charles went ahead quietly.”