Runners taking part in the annual event were given Heads Together headbands to raise awareness about mental health, and many are raising money for the campaign.
The royal trio took part in a Heart radio breakfast show, broadcast from the Global Academy.
Heads Together is a mental health initiative spearheaded by the duchess, Prince William and Prince Harry.
“Prince Philip was the real foodie in the sense that he loved to cook.”
Victims and their families, alongside the police, NHS hospital workers, fire brigade and ambulance teams took part in the service.
The Iraq and Afghanistan Memorial was created by the sculptor Paul Day and designed with two copper medallions — representing Iraq and Afghanistan — which sit in the middle of two large stones.
The royal couple went to a primary school in north London as a part of the duchess’ charity work for Place2Be, where she is a patron.
The actress — and, famously, girlfriend of Prince Harry — focused on work-to-weekend wear for Reitmans.
The young royals met with members of British business, charities and media to discuss their objectives for the year as a part of their work for Heads Together.
Proceeds of the sales will benefit Heads Together, the mental health campaign the duchess launched with the Duke of Cambridge and Prince Harry.
The royal trio attended the service at Thiepval Memorial alongside the Prince of Wales, Duchess of Cornwall, British Prime Minister David Cameron and French President Francois Hollande.