Prince Philip has been admitted to the King Edward VII Hospital in London.

The 99-year-old Duke of Edinburgh was taken to hospital on Tuesday as a precautionary measure on the advice of his doctor after feeling unwell, Buckingham Palace said in a statement. The palace said Philip is expected to remain in the hospital for a few days of observation and rest.

During Englands current coronavirus lockdown, he has been staying at Windsor Castle, west of London, with Queen Elizabeth .

Philip, who received a COVID-19 vaccine in January, has suffered a number of ailments over the years, including being treated for a blocked coronary artery at Papworth Hospital in Cambridgeshire, U.K., in December 2011.

He also suffered a bladder infection in June 2012, forcing him to miss the Queens Diamond Jubilee celebrations.

Exploratory surgery on his abdomen followed in June 2013.