The Duke of Edinburgh has spent a sixth night in hospital.
Philip, 99, received no further visits from royal family members on Sunday after his eldest son, the Prince of Wales, attended King Edward VII’s hospital in London on Saturday afternoon.
The duke was admitted to the hospital on Tuesday evening as a precautionary measure after feeling unwell. He is said to have walked in unaided.
Buckingham Palace said there was no update on the duke’s condition, having previously said he was “in good spirits”.
Charles was the first member of the royal family to visit the duke and it is understood that his visit was due to his father’s extended stay.
There were no further visits to the duke by family members on Sunday, though police and security cars remained in place at the hospital throughout the day.
Heart-shaped balloons and a letter written by a 10-year-old boy from north London, wishing the duke a quick recovery, were tied to the hospital railings.
Philip, who will turn 100 on June 10, is in hospital for an undisclosed reason although it is not coronavirus-related.
Royal author Penny Junor told PA: “We do all know he doesn’t like fuss, and he would regard a visit as fuss.”
She said she did not know the reason for Charles’ visit on Saturday, but added: “Momentous things are happening in the family at the moment and I suppose it’s perfectly possible that Charles wanted to go and talk to his father and reassure him about Harry.”
The hospital’s website states visitors will “only be considered in exceptional circumstances”.