Prince Philip, the 96-year-old husband of Britain’s Queen Elizabeth II, was admitted to hospital Tuesday evening as a “precautionary measure,” Buckingham Palace has told CNN.

The Prince, also known as the Duke of Edinburgh, was being treated at London’s King Edward VII Hospital for an infection arising from a pre-existing condition.

“Prince Philip is in good spirits and is disappointed to be missing the State Opening of Parliament and Royal Ascot,” Buckingham Palace said in a statement. The Queen, who will give her annual speech at the opening of Parliament today, will attend the Royal Ascot races later this afternoon.