The Duke of Edinburgh is to undergo surgery on his hip at a central London hospital later.
According to BBC, Buckingham Palace said Prince Philip was admitted to King Edward VII’s Hospital in Marylebone on Tuesday afternoon for the planned procedure.
The 96-year-old retired from royal duties last August.
Exact details of the duke’s condition have not been issued but his absence at the Easter service at Windsor was said to have been because of a hip problem.
He also did not attend two other recent events at Windsor Castle – the Royal Maundy Service at St George’s Chapel on 29 March and a parade on 22 March to mark Prince Andrew’s appointment as Colonel of the Grenadier Guards.
A statement released by Buckingham Palace to announce the treatment said: “Further updates will be issued when appropriate.”
The surgery comes ahead of a busy time for the royal family, with the Duchess of Cambridge due to give birth to her third child this month, and the wedding of Prince Harry and Meghan Markle in May.