In his role as Captain General of the Royal Marines, he met British naval servicemen who have taken part in a 1,664- mile trek as part of the challenge at a Buckingham Palace ceremony.
During the event Philip will also meet veterans and cadets before receiving the 1664 Global Challenge baton. The event certainly holds special significance to the prince, who was appointed captain general in succession to Queen Elizabeth II's late father, King George VI, almost 64 years ago.
The prince has been married to the Queen for 70 years.
In May, Buckingham Palace announced that Prince Philip would no longer be involved in public engagements after August of this year.
Good for her, then, that Philip remains healthy for a man of his age despite his two-night hospitalization in June for the treatment of an undisclosed infection.
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Priebus is the eighth top official to resign or be fired in the six months that Trump has been in office. Political analyst Scott Spradling said it became evident this week that Priebus's days were numbered.
The article referred to the 96-year-old's funeral and said it was going to be a "low key" service at St George's Chapel in Windsor Castle.
After Wednesday's event, Philip will no longer undertake royal engagements on his own, although he may still choose to attend certain events alongside Queen Elizabeth, 91, from time to time.
"Well you can't change the weather and you can't change the Prince", former Royal Marine James Ellard said, as he waited for the Duke to appear behind the gates.
Announcing his retirement in May, the palace insisted it was not a decision related to his health.
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He has been their Captain General since 1953, succeeding his father-in-law King George VI. (AFP) Britain's Prince Philip, Duke of Edinburgh, walking along the platform at London Paddington station in London.