Prince Louis was seen yawning and fidgeting during the service for his grandfather the King’s coronation.
The five-year-old royal attended Westminster Abbey with his parents the Prince and Princess of Wales and siblings Prince George and Princess Charlotte.
He held hands with his sister as the pair walked behind their parents as they made their way into the abbey.
During the first half of the ceremony, Louis could be seen letting out a big yawn, while also taking the opportunity to point out something of interest to his sister Charlotte.
Shortly afterwards, television footage showed he was no longer sitting in the row.
It is understood that plans were in place for him to leave the service at some point.
However, he returned for the national anthem at the end of the service and the procession out of the abbey. Footage showed him singing God Save The King.
Louis was regally dressed in a Hainsworth Garter Blue Doeskin Tunic with specially designed lace work embellishment to the collar, cuffs and fronts, made by bespoke Savile Row tailors Dege and Skinner.
The prince processed through Westminster Abbey and took his seat next to his mother and sister.
The deeply religious and solemn ceremony is two hours long. Louis was not at his great-grandmother Elizabeth II’s funeral in September.
Louis has become known for entertaining royal fans with his reactions during royal celebrations.
He was seen letting out a howl and clapping his hands over his ears on the Buckingham Palace balcony during the Platinum Jubilee flypast as his “Gan Gan” the late Queen told him what was happening.
He stood on his chair, waved his hands in the air, wriggled around and stuck his finger in his ear during the show.
In a personal tweet thanking those who turned out in 2022, William and Kate wrote: “We all had an incredible time, especially Louis… ”
The prince will process out of the abbey with Charlotte and his parents at the end of service and meet with George, who is acting as one of the King’s Pages of Honour.
The Wales family will then travel back to Buckingham Palace in a carriage as part of the grand coronation procession.