“As we said earlier, the doctor is acting very cautiously. The duke is still in a good mood,” the source said Friday.
The exact reason for admission has not been disclosed.
The 99-year-old took a step back from public life in 2017 and has been taken to hospital several times in recent years. In December 2019, he received hospital treatment for a pre-existing illness.
According to a royal source, his last admission was not an emergency and the Duke traveled to King Edward VII Hospital by car and entered it without assistance. The source added that the disease was not related to Covid-19.
The queen has stayed at Windsor Castle in west London, the source said at the time.
Prince Philip and Queen Elizabeth have received at least one dose of a Covid-19 vaccine.