Customers at a Little Chef in Doncaster were left stunned after the Duke of Edinburgh dropped in as they were enjoying breakfast.
Prince Philip spent 15 minutes at the diner on Great North Road while he was on his way to a private engagement last Thursday morning.
A member of staff at the diner, who did not want to be named, said: “He came in with all his entourage at about 9.30am.
“They did not have anything to eat but had a round of hot drinks.
“The person who served them at their table did not know who he was at first until someone mentioned. Everyone was surprised to have such a guest.”
She added the 93-year-old royal was not tempted to have the chain’s £10.99 ‘Royal Breakfast’ fry-up.
A Little Chef spokesman said: ‘Next time he might go for that.’