The Princess of Wales will remain in hospital for as long as two weeks after undergoing surgery, Kensington Palace has announced.
The overnight news came less than two hours before it was revealed King Charles III would be going to hospital for a corrective procedure on an enlarged but benign prostate.
The palace, in a statement about 1am on Thursday AEDT, said Kate went into hospital on Tuesday for planned abdominal surgery, which was successful, but would be away from public duties until April.
"The surgery was successful and it is expected that she will remain in hospital for 10 to 14 days, before returning home to continue her recovery," it said, in a statement issued overnight.
"Based on the current medical advice, she is unlikely to return to public duties until after Easter."
The palace said Kate understood the interest the news would generate but wanted privacy.
"She hopes that the public will understand her desire to maintain as much normality for her children as possible; and her wish that her personal medical information remains private," the statement said.
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"Kensington Palace will, therefore, only provide updates on her royal highness' progress when there is significant new information to share."
Kate wanted to apologise for postponing upcoming events and would try to reinstate "as many as possible, as soon as possible".
About an hour and a half after the news about Kate broke, Buckingham Palace said the King was headed for his own hospital visit.
"In common with thousands of men each year, the King has sought treatment for an enlarged prostate," the palace said, in a statement.
"His majesty's condition is benign and he will attend hospital next week for a corrective procedure.
"The King's public engagements will be postponed for a short period of recuperation."
After Prince Harry and Meghan's stormy departure to California in 2020, the Prince and Princess of Wales have solidified their position as being among the most popular members of the royal family.
Kate, in particular, has remained a reliable royal in the public eye — the smiling mother of three who can comfort grieving parents at a children's hospice or wow the nation by playing piano during a televised Christmas concert.
She was among the royals who appeared at the annual Christmas Day service at Sandringham.
- Reported with Associated Press