Prince Philip has spent a second night in hospital after feeling unwell.
On the advice of doctors, he will stay in the King Edward VII’s Hospital in London.
The Duke of Edinburgh, 99, was admitted for “observation and rest”.
He is said to be in “good spirits”.
It is believed the Prince felt unwell while at Windsor Castle – where he has been isolating with the Queen.
He was taken to hospital by car and walked in unaided as a “non-emergency admission”.
A Buckingham Palace statement said:
“His Royal Highness the Duke of Edinburgh was admitted to King Edward VII’s Hospital in London on Tuesday evening.
“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.”