King Charles III has been diagnosed with cancer and is suspending his public engagements to undergo treatment, casting a shadow over a busy reign that began less than 18 months ago after the death of his mother, Queen Elizabeth II.
The announcement, made by Buckingham Palace on Monday evening, came a week after the 75-year-old sovereign was discharged from a London hospital, following a procedure to treat an enlarged prostate.
The palace did not disclose what form of cancer Charles has, but a palace official said it was not prostate cancer. Doctors detected the cancer during that procedure, and the king began treatment on Monday.
News of Charles’ diagnosis reverberated through Britain, which, after seven decades of Elizabeth’s reign, has begun to get comfortable with her son. Charles waited longer to ascend the throne than anyone in the history of the British monarchy, and he was a familiar figure, with a personal life relentlessly dissected by the British media by the time he became the sovereign.
As king, however, Charles has become a confident elder statesman, putting a subtle but unmistakable stamp on the monarchy. He has traveled widely and spoken out on issues like climate change that have long been important to him.
Anxiety for Charles mixed with hope that he would recover swiftly. But in the absence of details about his condition, there was, inevitably, speculation, as royal watchers parsed the palace’s four-paragraph announcement.
“During the king’s recent hospital procedure for benign prostate enlargement, a separate issue of concern was noted,” the palace said. “Subsequent diagnostic tests have identified a form of cancer. His Majesty has today commenced a schedule of regular treatments, during which time he has been advised by doctors to postpone public-facing duties.”
Palace officials said the king would continue to carry out other duties, including his weekly meeting with the prime minister, as well as the daily pile of paperwork he completes as Britain’s head of state. Officials said there were no plans to appoint counselors of state to act in his place — a procedure that could signal that the sovereign was unable to fulfill his duties because of illness.
The palace said Charles “remains wholly positive about his treatment” and that he looked forward to resuming public engagements. He returned to London from his country residence, Sandringham, to begin treatment as an outpatient, palace officials said.
Charles, who ascended to the throne in September 2022, has generally been in good health. As a schoolboy, he suffered from recurring tonsillitis, but as an adult, he enjoyed vigorous sports like hiking, polo and skiing.
The king’s disclosure of the prostate treatment, and now of his cancer diagnosis, is unusual for the royal family, whose members often reveal little about their health. After the queen’s death at 96, the palace issued her death certificate, which listed her cause of death simply as “old age.”
Still, palace officials on Monday made clear that they would not issue regular updates on the king’s condition, and they asked reporters not to attempt to contact those involved in his treatment.
The palace said in its statement that the king had chosen to share his diagnosis “to prevent speculation and in the hope it may assist public understanding for all those around the world who are affected by cancer.”
The king’s younger son, Prince Harry, has been in touch with his father and planned to travel to Britain to visit him, according to the BBC. Harry has been largely estranged from the royal family since he and his wife, Meghan, announced they were withdrawing from official duties and moved to California.
Palace officials said Queen Camilla would continue to carry out a full program of official engagements during her husband’s treatment. She was a frequent visitor during his hospitalization for prostate treatment at the London Clinic, an elite private hospital in the city’s Marylebone neighborhood.
Charles’s illness caps a period of troubling health news for the royal family. Catherine, the wife of Prince William, was hospitalized for almost two weeks after undergoing abdominal surgery. She was released last week, but Kensington Palace has released few details about her recovery, which is expected to last until after the Easter holiday.
Sarah Ferguson, Duchess of York and ex-wife of the king’s younger brother, Prince Andrew, said recently that she had been diagnosed with melanoma, a serious type of skin cancer. It was her second cancer diagnosis within a year. Ms. Ferguson, 64, had spoken publicly about her decision to undergo a mastectomy and reconstructive surgery last year after a breast cancer diagnosis in the summer.
The news of the king’s illness brought an outpouring of well wishes from British and world leaders, and other public figures.
“Wishing His Majesty a full and speedy recovery,” Prime Minister Rishi Sunak posted on social media. “I have no doubt that he’ll be back to full strength in no time and I know the whole country will be wishing him well.”
President Biden, on a trip to Las Vegas, told reporters, “I’m concerned about him. Just heard about his diagnosis.” Mr. Biden, who was welcomed to Windsor Castle by the king last July, said he hoped to speak to Charles soon.
Michelle O’Neill, the Irish nationalist leader just named as first minister of Northern Ireland’s government, wrote on X, “I am very sorry to hear of King Charles illness and I want to wish him well for his treatment and a full and speedy recovery.”
Royal watchers were reluctant to speculate on how the king’s illness would affect the crown, given the paucity of information about his condition. Some pointed hopefully to the palace’s upbeat characterization of Charles’ mood.
“If the king becomes seriously unwell, then there will be constitutional questions to answer,” said Ed Owens, a royal historian who recently published a book, “After Elizabeth: Can the Monarchy Save Itself?” “Likewise, a prolonged period out of the public eye will require the rest of the royal family — already overstretched — to do more.”
Mr. Owens said the king’s age made worries about his health inevitable, adding, “It is moments like these that bring into sharp focus the very human, and potentially fragile, qualities of the U.K.’s constitution.”
In his brief time on the throne, Charles has been both a figure of continuity and change: conducting his life much as he has for decades, but embracing a more politically engaged role than his mother ever did.
Last year, he played host at Windsor Castle to the president of the European Commission, Ursula von der Leyen, after she signed a Northern Ireland trade agreement with Mr. Sunak. The timing drew criticism, since it appeared to give a royal imprimatur to the deal — in what some considered an improper intervention by the monarch in politics.
The king made two highly successful state visits to Europe, addressing the German Parliament in serviceable German, and drawing excited crowds during a walkabout with President Emmanuel Macron of France.
In December, Charles addressed the opening ceremony of the United Nations climate summit in Dubai, listing a litany of climate-related natural disasters that had afflicted the world in the last year: wildfires in Canada; floods in India, Pakistan, and Bangladesh; cyclones in the Pacific; and a drought in East Africa.
“We are taking the natural world outside balanced norms and limits, and into dangerous uncharted territory,” he said. “Our choice now is a starker and darker one: How dangerous are we actually prepared to make our world?”