Prince William, King Charles, Queen Camilla and Prince Edward Star in Regal New Portrait (Wearing Plumed Hats!)

Prince William, King Charles, Queen Camilla and Prince Edward are commemorating a special day in Scotland with a royal portrait for the books.

Members of the royal family took part in the Order of the Thistle Service at St. Giles' Cathedral in Edinburgh on July 3, part of this year's Royal Week in Scotland. While King Charles, 75, has been part of the greatest order of chivalry in Scotland since 1977 and Prince William, 42, has been a member since 2012, Queen Camilla, 76, and Prince Edward, 60, were officially welcomed into the Order of the Thistle during the service.

In a portrait shared on the royal family's official social media pages, Prince William, King Charles, Queen Camilla and Prince Edward posed together matching in the traditional garb: green velvet robes featuring the order's insignia and white-plumed hats.

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A video from the day was also shared on Prince William and Kate Middleton's joint social media accounts. The footage kicked off with a slow-motion clip of the Duke of Rothesay, as William is known in Scotland, walking in his robe and holding his hat before showing other members of the royal family — including Sophie, the Duchess of Edinburgh, who was on hand to support her husband, Prince Edward — chatting before the service.

After showing some scenes around Edinburgh, the video cut to the members of the order gathering for photos, showing Prince William and King Charles having a father-son chat between snaps. The reel ended with the new portrait.

The exact origins of the order are unknown, but legend states it was founded in 809 when King Achaius allied with Emperor Charlemagne, according to the royal family's website.

The Order of the Thistle recognizes 16 knights and ladies (not counting the members of the royal family) for their contribution to national life, and appointments are awarded as a personal gift from the monarch. 

The Order of the Thistle Service takes place every other year, with members processing to the Thistle Chapel in St. Giles' Cathedral. There, new members are installed by the monarch. The service is followed by a short reception in the Signet Library and lunch at the Palace of Holyroodhouse.

Prince William, King Charles and Queen Camilla sported their Order of the Thistle robes on July 5, 2023, when they gathered for Scotland's celebration of the coronation two months after the monarch was officially crowned at Westminster Abbey. While all three royals wore the ceremonial robes and Camilla added the hat, Princess Kate attended the event in a previously worn blue coat by Catherine Walker, a coordinating headpiece by Philip Treacy and a pearl choker necklace from the late Queen Elizabeth’s jewelry collection. That's because the Princess of Wales (or Duchess of Rothesay, as she's called in Scotland) is not part of the Order of the Thistle.

For King Charles and Queen Camilla’s coronation in May 2023, Princess Kate wore the Royal Victorian Order mantle reflecting her status as a Dame Grand Cross of the Royal Victorian Order.

Although Princess Kate, who is undergoing cancer treatment, made her first public appearance in six months at Trooping the Colour on June 15, palace aides stressed that the outing did not signify an official return to royal work.

Kate, 42, said in a June 14 message that she hopes to "join a few public engagements over the summer, but equally knowing I am not out of the woods yet."