Prince Philip, 96, the husband of Britain’s Queen Elizabeth II, left hospital on Thursday after treatment for an infection, Buckingham Palace said.
The palace said earlier that the prince, also known as the Duke of Edinburgh, had been admitted to London’s King Edward VII Hospital on Tuesday night, “as a precautionary measure, for treatment of an infection arising from a pre-existing condition”.
It said he was “in good spirits” and disappointed that he was forced to miss Wednesday’s state opening of parliament and horse-racing at Royal Ascot.
The queen, 91, delivered her speech to the parliament and attended Royal Ascot as planned on Wednesday.
Prince Philip announced in April that he had decided not to carry out any more public duties after August.
He has been treated in hospital several times for bladder infections in recent years.