Ladies and Knights of the Garter processed through the grounds of Windsor Castle for the annual service commemorating the country’s oldest and most senior order of chivalry.
Charles and Camilla followed tradition and were at the back of the procession, dressed in white plumed hats and dark blue velvet robes as were the other members of the order, including the Prince of Wales, Princess Royal and Duke of Edinburgh.
The King’s appearance comes just two days after the Trooping the Colour ceremony where he was joined by fellow cancer patient the Princess of Wales, who did not attend Garter Day.
Among the members of the Order taking part in the procession were former prime ministers Sir Tony Blair and Sir John Major, along with Baroness Amos.
The Duke of York, a member of the order, did not join the service.
Andrew stepped down from public life after the furore over his friendship with convicted sex offender Jeffrey Epstein and paid millions to settle a civil sexual assault case with Virginia Giuffre, a woman he claimed never to have met.
The ceremony heralds a busy period for the royals, with the King and Queen expected at Royal Ascot in the coming days, and the following week they will host a state visit by Japan’s Emperor.
Hundreds of spectators lined the procession route with many taking hampers and camping chairs to add a summer picnic feel to the occasion.
At one point between the procession, William looked over to where the Duchess of Edinburgh and Vice Admiral Sir Tim Laurence were watching the spectacle and grinned.
The installation of new Companions of the Order – including composer Andrew Lloyd-Webber, who has been made a Knight Companion – took place during the service.
Theatre impresario Lord Lloyd Webber, whose hit musicals include The Phantom Of The Opera, Cats, Jesus Christ Superstar and Joseph And The Amazing Technicolor Dreamcoat, attended a private investiture in the castle’s Garter Throne Room earlier in the day.
Also invested were the Duchess of Gloucester as a Royal Lady of the Garter, as well as Lord Kakkar, emeritus professor of surgery at University College London, and Air Chief Marshal the Lord Peach, who have both been made Knight Companions.
The Garter, founded in 1348 by Edward III, is awarded by the sovereign for outstanding public service and achievements.
After the service, the royals took part in a traditional carriage procession back up the hill to the castle.
The carriages travelled quickly and first Charles and Camilla left by coach followed by Edward, Sophie and William together, and then Anne and her husband Sir Tim.