British Prime Minister Rishi Sunak confirmed Tuesday that King Charles III's cancer was caught at an early stage.
The announcement comes amid reports that Charles's estranged son Prince Harry flew back to London, raising hopes of a family reconciliation.
Harry, who now lives in California with his actress wife Meghan and their children, has been at war with his family since quitting royal life and launching a barrage of score-settling criticism in his best-selling autobiography "Spare."
The Daily Mail reported that Harry had "jumped on a plane so he could be in the U.K. later today" while The Times said he was expected to touch down in London shortly after 12 p.m. GMT.
Hopes of a rapprochement with Charles and Harry's brother William, who is heir to the throne, come after Buckingham Palace made a shock announcement that Charles had been diagnosed with cancer and begun treatment.
U.K. Prime Minister Sunak said earlier that the cancer had been "caught early."
Buckingham Palace has not specified the type of cancer afflicting the 75-year-old monarch, who will now step back from public-facing royal duties to complete his treatment.
Charles is just 17 months into his reign having waited decades to begin the job he was born to do following the death of his 96-year-old mother, Queen Elizabeth II, on Sept. 8, 2022.
Citizens expressed shock and sympathy at the news.
"We were just incredibly sad and hope ... that he gets over it," said retiree Sue Hazell, from the northern English city of Doncaster, as she visited Buckingham Palace.
"It's not nice to hear anyone's been diagnosed with cancer," added Sarah Firisen, 55, a software sales worker.
"I feel kind of bad for him. He waited all these years to be king."
Charles's diagnosis will prolong a frontline shortage of royals created by Charles's admission to the hospital last month for a benign prostate procedure and the almost simultaneous hospitalization of Catherine, Princess of Wales.
The royals' health issues have left 76-year-old Queen Camilla as the highest-profile royal with support from Charles's sister Princess Anne, 73.