Prince Philip, the husband of Queen Elizabeth II, was admitted to a London hospital Friday "as a precautionary measure," Buckingham Palace said.
The palace said the 98-year-old Philip was admitted to the King Edward VII hospital for observation and treatment of a pre-existing condition.
"The admission is a precautionary measure, on the advice of His Royal Highness' doctor," the palace said in a statement.
Philip had been at the royal family's Sandringham estate in eastern England, where the Queen and her family usually spend Christmas. The palace said Philip didn't travel by ambulance and his admission wasn't an emergency. He is expected to be in hospital for a few days.