Prince Philip has left hospital in time to celebrate his 91st birthday.

The husband of Queen Elizabeth thanked staff at London's King Edward VII Hospital Saturday after spending five days there for treatment for a bladder infection.

Philip got into the front passenger seat of a Land Rover before being whisked off under police escort.

He nodded when reporters shouted out questions about whether he was feeling better.

Philip turns 91 on Sunday.

A day before going to hospital, he was by the Queen's side on the River Thames last Sunday to celebrate her Diamond Jubilee, marking 60 years on the throne. He had to miss a concert Monday evening outside Buckingham Palace.

The Duke of Edinburgh will celebrate his birthday privately with members of the royal family.