King Charles received a cancer diagnosis less than one year into his reign, which caught even palace insiders off guard. The palace has provided scant details on his condition.

This week’s PEOPLE cover story features an exclusive extract on King Charles’ shocking cancer crisis. 

On Feb. 4, the royal family used social media to highlight World Cancer Day.

On Cancer Day, Queen Camilla was photographed at a new cancer support center in the U.K. Later that morning, King Charles, 75, accompanied by Camilla, 76, attended a morning service at St. Mary Magdalene Church near their country retreat in Sandringham.

The monarch, who is still recovering from his Jan. 26 operation for a benign enlarged prostate, cheerfully waved to well-wishers. He offered no hint of the impending announcement that would shake the world a day later. The palace revealed that Charles has cancer in a 138-word statement. The statement concluded with the message that His Majesty has chosen to share his diagnosis to prevent speculation and to assist public understanding for all those around the world who are affected by cancer.

The palace revealed that during Charles’ prostate procedure, a separate health issue was detected. Subsequent diagnostic tests have shown the presence of a form of cancer. The type of cancer has not been disclosed, but it is not prostate cancer.

Robert Hardman, author of The Making of a King, stated that more information may become available. PEOPLE exclusively reports on King Charles III and the Modern Monarchy in this week’s issue.  

 The palace statement added that the King has started ‘regular treatments’ and will temporarily postpone public duties. Charles ‘remains wholly positive about his treatment and looks forward to returning to full public duty as soon as possible.’

Those close to the family were surprised by the announcement. ‘I was shocked when I heard it,’ says a palace insider.

According to a source who knows him, ‘He has not looked himself.’ The source attributed this to grief, as Prince Charles had experienced two deaths close together – his mother, Queen Elizabeth, in September 2022 and his father, Prince Philip, in April 2021. However, it is possible that he was unwell without realizing it, which would have taken a toll on him.

This news comes just nine months into Charles’s reign and only 17 months after Queen Elizabeth’s death at the age of 96.

The royal family has had a difficult start to the new year. On Jan. 16, Princess Kate underwent a 13-day hospitalization for abdominal surgery. This prompted Prince William to temporarily withdraw from public duty to care for Kate and their three children: Prince George, Princess Charlotte, and Prince Louis.

The royal family’s thinned ranks have been highlighted again with the potential for increased responsibilities for Charles’s son and heir, William, 41. Prince Harry, 39, has departed, and Charles’s scandal-plagued brother, Prince Andrew, 63, has been removed. 

According to a palace insider, Charles wants to get on with the job, but that will depend on the treatment he is receiving. It may be utterly draining, and he will need much support.