Prince Charles visited Prince Philip on February 20, who was hospitalized four days ago on the advice of a doctor as a precaution.
Prince Charles, 72 years old, wearing a mask, entered the back door of King Edward VII Hospital in central London.
Prince Philip, 99 years old, was hospitalized on February 16 after feeling unwell.
His Highness is expected to continue to stay in the hospital next week for monitoring and rest.
Mr. Philip was briefly hospitalized at the end of 2019. His Majesty stopped taking on official duties in August 2017 and rarely appeared in public.
During the time Britain imposed restrictions against Covid-19, he stayed at Windsor Castle, west London, with Queen Elizabeth.