LONDON — Catherine, Princess of Wales, has been greeted with an outpouring of support and sympathy after she revealed Friday she had been diagnosed with cancer and was in the early stages of chemotherapy treatment.

King Charles III said in a statement he was “so proud of Catherine for her courage in speaking as she did,” and that he had “remained in the closest contact with his beloved daughter-in-law throughout the past weeks.”

Last month, Charles postponed public duties as Buckingham Palace revealed he had been diagnosed with cancer. Neither Charles, 75, nor Catherine, 42, have disclosed the type of cancer they have.

However, Catherine, in particular, faced weeks of intense speculation about her health and whereabouts after she took time away from the public eye following major abdominal surgery in January.

On Saturday, Britain’s newspaper front-pages were inked with support and well-wishes for the princess, while leaders across the globe also made statements of support.

British Prime Minister Rishi Sunak commended Catherine’s “tremendous bravery” and said she had “the love and support of the whole country as she continues her recovery.”

President Biden said, “Jill and I join millions around the world in praying for your full recovery.” Canadian Prime Minister Justin Trudeau said, “On behalf of Canadians, I’m sending my support as she undergoes treatment. We’re all wishing her a swift recovery.”

Catherine’s younger brother, James Middleton, posted a childhood photo online of the siblings hiking, with a message: “Over the years, we have climbed many mountains together. As a family, we will climb this one with you too.”

Prince Harry and Meghan, the Duchess of Sussex, released a statement wishing “health and healing for Kate and the family,” adding that they hoped their sister-in-law could heal “privately and in peace.”

In her prerecorded video released Friday, Catherine said, “it has been an incredibly tough couple of months for our entire family.” She said tests after her abdominal surgery had revealed cancer and that she was in the early stages of “preventative chemotherapy.”

While she was “well and getting stronger every day,” the news had been a “huge shock,” Catherine said, adding that she and her husband, Prince William, had been “doing everything we can to process and manage this privately for the sake of our young family.”

Following Catherine’s announcement, there has been growing criticism about the swirl of media scrutiny and online conspiracy theories she has faced. British and international outlets had covered the speculation extensively, while the subject was even joked about on-air by late-night host Stephen Colbert.

On Saturday, the Sun tabloid wrote on its front page: “Kate, you are not alone,” while a Daily Mail front page op-ed wondered, “How do all those vile online trolls feel now?” Both newspapers, along with most other news outlets, had covered her whereabouts — and lack thereof — extensively in recent weeks.

Many online commentators have expressed regret at the jokes they had made at Catherine’s expense — while noting that the palace was widely seen to have bungled its communications of the whole affair, including by releasing a photo of the princess and her children that had been edited.

British publicist Mark Borkowski said in an interview Saturday it had been a “roller coaster” for royal PR, but the video was proof the royal family remains “a very powerful institution, it has an ability to regain control.”

Borkowski said the carefully made video released by Catherine was “extraordinary” and a “tidal wave” sweeping away all of the conspiracy theorists and doubters. “One has to praise the poor woman for showing so much dignity and grace.”

He noted that Catherine and other female members of the royal family, including “Margaret, Fergie, Diana,” traditionally contended with more “misogynistic treatment by the media” than their male counterparts. Borkowski was referring to Princess Margaret; Sarah Ferguson, the Duchess of York; and Princess Diana, the late mother of Catherine’s husband.

“You have to be part-fashion model, part-soft politician to be a woman in the royal family,” Borkowski said. “They have to work harder … and Kate is box-office royal family on the front page of every tabloid in the world.”

While Charles was able to tell the nation about his cancer diagnosis in February via a statement from Buckingham Palace, Borkowski noted that Catherine had to be seen.

“If it had been a statement, no one would have believed it and maybe all the crazy rumors would have carried on percolating. Now, there’s a massive full stop … and a clear call for privacy.”

There is some online debate over whether Harry and Meghan, who stepped back from royal duties in 2020 and moved to the United States, should return or take up more responsibilities amid a slimmed down senior royal family. Borkowski said he thought it was “very, very unlikely” the couple would return from California. “The wedge is too deep,” he said. “That would just generate so much negative publicity.”

Britons on Saturday expressed sympathy for Catherine and her family, and they stressed her right to privacy.

“I feel sad for her and sorry for her, as I would anybody who’s been diagnosed with cancer — especially when they’re so young and have children,” Veronica Wasilwa, 68, said.

Wasilwa added that Catherine was “entitled to privacy,” although she noted the run of bad health news for the royal family had also humanized them, as she saw “they’re going through what normal families go through.”

Ange Anderson, 65, said: “I felt that she must have felt pressurized to share it with the public, which is a shame.”

Anderson, whose sister-in-law recovered from breast cancer a few years ago, admitted “a small part of me wants to know what type of cancer she has, but I don’t think it’s my entitlement know.”

Michelle Mitchell, head of British charity Cancer Research UK, said in a statement that nearly one in two Britons will develop cancer in their lifetime, and “many more are affected when someone they love is diagnosed with cancer.”

She added that “high profile cancer cases often act as a prompt to encourage people to find out more or think about their own health.” Mitchell wished Catherine “a full, swift recovery and return to good health.”

Amid the spate of difficult health news from the palace in recent weeks, Borkowski said, Catherine’s video would also serve to remind the public that behind the pomp and pageantry of the British monarchy, there was a family with real people.

“At the heart of it, it’s very, very human what they’re going through,” he said. Now, “I think the royals will be looking for sunnier days.”