Prince Philip has been moved to a different hospital and will continue to be treated for an infection.
The Duke of Edinburgh, 99, was admitted to King Edward VII’s Hospital in London just under two weeks ago as a “precautionary measure” after feeling unwell.
A Buckingham Palace statement said: “The Duke of Edinburgh was today transferred from King Edward VII’s Hospital to St Bartholomew’s Hospital where doctors will continue to treat him for an infection, as well as undertake testing and observation for a pre-existing heart condition.
“The Duke remains comfortable and is responding to treatment but is expected to remain in hospital until at least the end of the week.”
His condition is not related to coronavirus.
Last week, Prince Edward told Sky News his father was doing “a lot better” and that the family were keeping their “fingers crossed”.
The prince said he was “looking forward to getting out, which is the most positive thing”.
Asked if the duke was frustrated, Prince Edward added: “Just a bit! I think that gets to all of us, and then, you can only watch the clock so many times and the walls are only so interesting.”
Prince Phillip was driven to the central London hospital on 16 February, with a royal source saying he walked in unaided.
Prince Charles was pictured in a face mask going in to visit his father a few days later and stayed for about half an hour.