Prince Philip pulled out of the annual Maundy Service at Windsor Castle on Thursday because he is suffering from a hip problem.
It meant the Queen attended the service at St George’s Chapel alone.
Prince Philip, who is 96, officially retired from public duties last year, but his name had appeared on Thursday’s order of service.
That forced Buckingham Palace to confirm that the Duke had to change his plans.
Palace aides do not routinely comment on the Duke’s health, but their hand was forced today as Prince Philip’s name was printed in black and white.
A Palace spokesperson said: "The order of service was printed some weeks ago when it was hoped the Duke would be able to take part. His Royal Highness has since decided not to attend."
Last week, it is thought the hip problem forced him to cancel another engagement, also at Windsor Castle, that he had hoped to attend.
His son, Prince Andrew was appointment Colonel of the Grenadier Guards – a role the Duke of Edinburgh used to hold.
The Duke did not go to that ceremony.