The British Prince Philip (99) was taken to another hospital on Monday, Buckingham Palace said on Monday.
The prince had been admitted to King Edward VII Hospital in London for an unknown reason since February 19 and the royal family now reports that it is an infection, for which he is further treated.
"The Duke of Edinburgh was transferred today from King Edward VII's Hospital to St Bartholomew's Hospital, where he is being treated for an infection," Buckingham Palace said.
The prince will also receive an examination for his pre-existing heart condition.
The prince is expected to stay here until at least the end of the week.
Spokespersons for the royal family say that Philip is responding well to the treatment and that he is doing well under the circumstances.
Earlier, his grandson William already announced that Prince Philip was "okay".
Buckingham Palace also gave reassuring reports and said that it is in any case not a contamination with the corona virus.
It is not the first time that Philip has been taken to hospital.
This previously happened in December 2019. In April of the year before, he was operated on his hip.
In June 2017, the prince was also in hospital because of an infection caused by previous health problems.
In 2013, Philip was hospitalized after pain in his lower abdomen.
The Prince celebrated his 99th birthday with his wife Queen Elizabeth II at Windsor Castle in June.
The two have been in isolation there since March because of the corona virus.