LONDON — Kate, the Princess of Wales, has cancer and is undergoing chemotherapy, she revealed Friday in a stunning announcement that followed weeks of speculation about her health and whereabouts.

The princess disclosed her condition in a video message recorded Wednesday in Windsor and broadcast Friday. It came after relentless speculation on social media ever since January, when she was hospitalized for unspecified abdominal surgery.

Kate asked for “time, space and privacy” while she is treated for an unspecified type of cancer that was discovered after what she described as “major” surgery.

Wearing a casual striped sweater and jeans, Kate sat on a wooden bench in front of a lawn dotted with daffodils. The flowers, which bloom in early spring, are often used as a symbol of hope for people fighting cancer.

“I am well,” she said. “I am getting stronger every day by focusing on the things that will help me heal.”

Kate, 42, hadn't been seen publicly since Christmas until video surfaced this week of her with her husband, Prince William, heir to the throne. It showed them walking from a shop that sells produce grown on the royal family's Windsor estate.

The news is another jolt for the royal family since the announcement last month that King Charles III was being treated for an unspecified type of cancer that was discovered while undergoing a procedure for a benign enlarged prostate.

Charles said he is “so proud of Catherine for her courage in speaking as she did,” according to a statement released by Buckingham Palace. The king, who received prostate treatment in the same hospital and at the same time Kate had her surgery, remained in the “closest contact with his beloved daughter-in-law” in the past weeks.

The king and Queen Camilla “will continue to offer their love and support to the whole family through this difficult time,” the palace said.

Prince Harry and his wife Meghan, who have been estranged from William and Kate since their move to California in 2020, wished the princess well.

“We wish health and healing for Kate and the family, and hope they are able to do so privately and in peace,” they said in a statement.

Before Friday, Kensington Palace had given little detail about Kate's condition beyond saying it wasn't cancer-related, the surgery was successful and recuperation would keep the princess away from public duties until April. Kate said it had been thought that her condition was non-cancerous until post-surgery tests revealed the diagnosis.

“This of course came as a huge shock, and William and I have been doing everything we can to process and manage this privately for the sake of our young family,” she said.

By choosing to speak directly to the country and the world about her condition, rather than issuing a statement through the palace, Kate offered a level of intimacy and transparency atypical of a member of the royal family and may help tamp down runaway conjecture. The king's disclosure of his condition was also notably open by royal standards.

Kate said it had taken her time to recover from the surgery before starting “preventative” treatment, which she said was in the early stages.

Dr. Shivan Sivakumar, associate professor in oncology at the University of Birmingham, said it's unclear what the princess meant by “preventative” chemotherapy but he presumed that it's what is known as “adjuvant” chemotherapy in the medical profession.

“This is chemotherapy after an operation to prevent recurrence,” he said. “This is to attempt to destroy any circulating cancer cells.”

Kate said it has been “an incredibly tough couple of months” for her family. She said it had taken time to tell her three children Prince George, Princess Charlotte and Prince Louis in a way “appropriate for them” and reassure them she will be OK.

The announcement came after the start of the Easter holidays, which will shield the children from media coverage of the news.

British Prime Minister Rishi Sunak said in a statement that Kate “has shown tremendous bravery.”

“We are incredibly sad to hear of the news,” said White House Press Secretary Karine Jean-Pierre, who opened her briefing with reporters moments after news of cancer treatment broke. “We are taking this in, this terrible news, as all of you are.”

Charles, 75, has withdrawn from public duties while he has cancer treatment, though he's appeared frequently in photos carrying on meetings with government officials and dignitaries and was even seen going to church.

Kate, on the other hand, had been out of view instead of appearing at charity events and promoting causes such as supporting children early in life, leading to weeks of speculation and gossip. Attempts to put rumors to bed by releasing a photo of her on Mother's Day in the U.K. surrounded by her three smiling children backfired when The Associated Press and other news agencies retracted the image because it had been manipulated.

Kate issued a statement the next day acknowledging she liked to “experiment with editing” and apologizing for “any confusion” the photo had caused. But that did little to quell the speculation.

Even the footage published by The Sun and TMZ that appeared to show Kate and William shopping sparked a new flurry of rumor-mongering, with some armchair sleuths refusing to believe the video showed Kate at all.

Earlier this week, a British privacy watchdog said it was investigating a report that staff at the private London hospital where she was treated tried to snoop on her medical records while she was a patient for abdominal surgery.

The former Kate Middleton, who married William in a fairy-tale wedding in 2011, has boosted the popularity and appeal of the British monarchy worldwide more than any royal since Princess Diana.

The princess is the oldest of three children brought up in a well-to-do neighborhood in Berkshire, west of London. The Middletons have no aristocratic background, and the British press often referred to Kate as a “commoner” marrying into royalty.

Her brother James Middleton posted on Instagram: “Over the years, we have climbed many mountains together. As a family, we will climb this one with you too.”

Kate attended the private school Marlborough College and then University of St. Andrews in Scotland, where she met William around 2001. Friends and housemates at first, their relationship became widely publicized when they were pictured together on a skiing holiday in Switzerland in 2004.

Kate graduated in 2005 with a degree in art history and a budding relationship with the prince.