Britain's King Charles III was on Friday admitted to a private hospital here for treatment for an enlarged prostate, Buckingham Palace announced.
The procedure will be carried out at the London Clinic private hospital, where Catherine, the Princess of Wales, had surgery last week.
The 75-year-old King visited the Princess of Wales in the hospital this morning, ahead of his own scheduled treatment.
It is not yet known how long King Charles will remain in hospital.
King Charles III had made his health problem public as a way of sending a message to other men to get their prostates checked.
A statement from Buckingham Palace said the King was "delighted to learn that his diagnosis is having a positive impact on public health awareness".
He also thanked those who had "sent their good wishes," the BBC reported.
The plan for King Charles to have a "corrective procedure" for his enlarged prostate was revealed by the palace last week.