The Duke of Edinburgh's final solo royal engagement was hailed as "historic" by a Royal Marine whose feat of strength and endurance was celebrated by the retiring royal.
As a former Royal Navy officer Philip's last official event, after almost 70 years championing his own causes and charities, fittingly featured men from the Royal Marines - an integral part of the Navy.
The Duke was praised for his role as Captain General of the Royal Marines by a senior officer who described the 96-year-old as a "wonderful figurehead for all Royal Marines to look up to".
The event marked the end of the 1664 Global Challenge, a series of exploits that have pushed marines from the Corps to their physical limits in aid of the Royal Marines Charity.
The challenge, which recognises 1664, the year the Corps was founded, has seen Royal Marines all over the world fundraising, including Corporal Will Gingell, 33, and Corporal Jamie Thompson, 31, who have run 1,664 miles over 100 days.
Cpl Thompson, from Carlisle but based in Plymouth, whose epic marathon ended earlier, said:
"This is historic because this is the Duke's last royal engagement and we're a part of it, the Royal Marines are a part of it - so it's an absolute honour."
The Queen's Consort announced in May he would be retiring from royal engagements, a decision which was fully supported by the Queen and was not medically related.
Buckingham Palace has stressed although the Duke's diary of engagements has come to an end he may decide to attend certain events, alongside the Queen, from time to time.
The Queen's public schedule continues as normal but other members of the Royal Family will step up in support of the monarch in her role as head of state.
The historic day began with the Duke stood on a dais in the palace's forecourt where he received the royal salute from an honour guard of Royal Marines.
Lieutenant Colonel Gary Green, who devised the 1664 Global Challenge, said:
"It's an honour for the Armed Forces having the Duke of Edinburgh's last public engagement with the Corps and the Royal Navy - it's brilliant, we're delighted."
He added: "The Duke of Edinburgh is all about challenges, he's all about charity work and helping people and having somebody like the Duke as head of the Royal Marines, it just helps the Corps with our own challenges.
"With somebody who's head of the Corps, who's quite exceptional in what he does, it makes the Corps exceptional, it builds our Commando spirit and he's a wonderful figurehead for all Royal Marines to look up to."
As part of the 1664 Global Challenge Royal Marines from around the globe have also been taking part in extreme events including a 34-mile swim underwater and a company of Royal Marines lifting more than 20,000 tonnes and running 10,000 kilometres.