Buckingham Palace has announced that King Charles III has been diagnosed with cancer. In a statement, the palace explained that his condition was discovered when he was being treated for benign prostate enlargement at the London Clinic last month. The palace did not share further details about his diagnosis, however Vanity Fair can confirm that the condition is not prostate cancer.

“During The King’s recent hospital procedure for benign prostate enlargement, a separate issue of concern was noted. Subsequent diagnostic tests have identified a form of cancer,” the statement read. “His Majesty has today commenced a schedule of regular treatments, during which time he has been advised by doctors to postpone public-facing duties. Throughout this period, His Majesty will continue to undertake State business and official paperwork as usual.”

The king has been taking time off from his royal duties since he announced his prostate condition last month. Before the palace announcement of his cancer diagnosis, he was expected to return to royal duties in a month, and he was photographed attending church with Queen Camilla on Sunday. On Monday, he traveled from the Sandringham Estate to his home in London to begin treatment as an outpatient.

In its statement, the palace thanked the clinicians who identified the king’s condition and shared their reasoning for making the public announcement. “The King is grateful to his medical team for their swift intervention, which was made possible thanks to his recent hospital procedure,” it read. “He remains wholly positive about his treatment and looks forward to returning to full public duty as soon as possible. His Majesty has 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.”

Sources close to the king say that the news has come as “a shock” as Charles was recuperating at Sandringham when he got the news. “He was recuperating well, albeit a little impatiently, he was very eager to get back to work,” a source told Vanity Fair. “The cancer diagnosis has come as a pretty major shock for the king and everyone in the family. But the monarch is under the best possible health care and hopefully they have caught the cancer early.” 

Charles will be treated as an outpatient and is expected to stay at Clarence House his London residence while he undergoes treatment.

Meanwhile, Prince Harry is heading to the UK to see his father, sources close to the Duke of Sussex have said. Charles and Harry have been having conversations since the king's 75th birthday in November. 

The news comes at the end of the month in which the royal family has shared an unprecedented amount of information about their health statuses. On January 16, Kate Middleton underwent a planned abdominal surgery at the London Clinic, and on January 22, Sarah Ferguson announced that she had been diagnosed with a form of skin cancer, following a breast cancer diagnosis last summer. One day after the king shared the news about seeking treatment for benign prostate enlargement, the NHS announced that visitors to its relevant informational site had increased by 1000% overnight.