The Duke of Edinburgh has been admitted to hospital for planned surgery on his hip which will take place on Wednesday, Buckingham Palace has said.
Philip, who is 96, is said to have complained of a problem with his hip which caused him to miss a Windsor Castle event with the Queen last week.
At the time the Queen's consort was said to be experiencing some trouble with the joint.
Buckingham Palace said in a short statement: "His Royal Highness the Duke of Edinburgh was admitted to King Edward VII Hospital in London this afternoon, for planned surgery on his hip which will take place tomorrow."
The duke stepped down from his public duties last summer but on occasion does attend events with the Queen.
When it was announced last year that he would be retiring from official engagements, Buckingham Palace stressed that the decision was not health-related and he had the full support of the Queen.