The 86-year-old husband of Queen Elizabeth II was admitted to the hospital last week and underwent several days of monitoring, CNN reported.
In total, the Duke of Edinburgh spent three nights at King Edward VII Hospital and now will attempt to regain his strength at Windsor Castle, palace officials said.
The BBC said all of Philip's scheduled events for Monday have already been canceled, adding to the growing list of the events the royal has missed since falling ill.
Last week, the duke's officials canceled several of his engagements including a memorial dedicated to Sir Edmund Hillary and a cancer fundraiser. Hillary was one of the first people in the world to successfully reach the peak of Mount Everest.