The husband of Britain's Queen Elizabeth II, Prince Philip, was admitted to hospital in London on Tuesday evening as a precautionary measure, Buckingham Palace said.
The 99-year-old prince, who is also known as the Duke of Edinburgh, has been admitted to hospital several times in recent years.
"The Duke's admission is a precautionary measure, on the advice of His Royal Highness's Doctor, after feeling unwell. The Duke is expected to remain in hospital for a few days of observation and rest," the statement said.