King Charles and Queen Camilla were joined by the Prince and Princess of Wales for a National Service of Thanksgiving and Dedication at St Giles' Cathedral, which is essentially the monarch's Scottish coronation.
The ceremony involves Charles, 74, being presented with the Honours of Scotland (Crown Jewels) and his son Prince William, along with his wife Princess Kate, was there to watch proceedings.
As well as being the Prince and Princess of Wales, the couple hold the Scottish titles of Duke and Duchess of Rothesay, so it's only fitting that they were in attendance.
The Crown, the Sceptre and the Sword of State travelled to the cathedral by car under military guard.
Here are the best photos of Prince William and his wife Princess Kate…
The Princess stunned in a coat dress by Catherine Walker, one of her go-to designers and she paired the beautiful piece with a matching hat by Philip Treacy. She also co-ordinated her bag and heels with her outfit.
Eagle-eyed fans may have noticed that Princess Kate's necklace is a familiar item, as it is from the late Queen Elizabeth II's collection.
Meanwhile, William looked terribly smart in his RAF No1 Uniform adorned with medals, and a ceremonial cloak. The royal also proudly wore the 'Lesser George' sash badge.
As the ceremony was underway, the Princess picked up a hymn sheet to sing along with the congregation.
What medals is William wearing?
The medals seen on William's chest are for the Golden Jubilee, Diamond Jubilee, Platinum Jubilee and Coronation Most Ancient and Most Noble Order of the Thistle Mantle and Collar with the 'St Andrew'.
The King and Queen kicked off Royal Week on Monday, with Charles participating in the Ceremony of the Keys at the palace, and joining former sailors aboard the Royal Yacht Britannia to mark 25 years since she arrived in Edinburgh.