The Duke of Edinburgh remains in hospital after he was admitted on Tuesday evening as a precaution due to feeling unwell.
Prince Philip, 99, was said to be in “good spirits” after being taken to King Edward VII Hospital in central London.
His stay is not related to coronavirus and a palace source said the duke walked into the hospital unaided.
He is expected to be there for a few days of observation and rest.
The Queen, 94, has remained at Windsor Castle. On Wednesday, she spoke by telephone to the First Sea Lord, Admiral Tony Radakin, about the work of the Royal Navy at home and abroad.
Prince Charles and the Duchess of Cornwall also carried out official duties on Wednesday, visiting the Queen Elizabeth Hospital in Birmingham to speak to patients and NHS staff.
