Prince William, Prince George and Princess Charlotte Support Kate Middleton at Christmas Carol Service

'Tis the season for Kate Middleton's Together at Christmas carol service.

The Princess of Wales, who hosted the Dec. 15 festivities at London's Westminster Abbey, attended with her husband, Prince William, and their two eldest children Prince George, 9, and Princess Charlotte, 7. However, it appears that their youngest child, Prince Louis, 4, did not join them.

For the occasion, Kate wore a burgundy coatdress by Eponine London, with Charlotte twinning in a coordinating ensemble. Meanwhile, William and George both sported dark coats over their suits, white button-down shirts and ties.

They weren't the only members of the royal family in attendance. King Charles III, Queen Consort Camilla, Sophie, Countess of Wessex, Princess Eugenie and her husband Jack Brooksbank, Princess Beatrice and her husband Edoardo Mapelli Mozzi, Zara and Mike Tindall and the Duke and Duchess of Gloucester were among those taking the carols. Kate's parents, Carole and Michael Middleton, as well as her siblings Pippa and James Middleton, joined them for the service as well.

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According to a message from Kensington Palace, the event recognized "the selfless efforts of individuals, families and communities across the U.K., and celebrate and showcase the joy that human connection and togetherness can bring." It also honored Queen Elizabeth II, who died at the age of 96 in September. Among the tributes to Her Majesty was a Christmas tree decorated with Paddington Bear ornaments.

The Westminster Abbey choir performed at the event as did Craig David, Alexis Ffrench, Samantha Barks, Alfie Boe and Mel C. Kate also introduced the service, and William, Kristin Scott Thomas, Hugh Bonneville and Kadeena did the readings. In addition, Catherine Zeta-Jones will narrate the service's broadcast program, which will air on ITV1 on Christmas Eve.

According to the note from Kensington Palace, other guests were recognized for their "tireless work to help and care for those around them."

"Thank you to everyone who has helped make #TogetherAtChristmas so special," a post to William and Kate's official Instagram account read, "it was fantastic to celebrate inspiring individuals and outstanding organisations with you all."

The post also included a shout-out to one particular young fan. "Theo," the message continued, referencing 4-year-old Theo Compton who presented Kate with a bouquet of flowers in Wales in September, "great to see you again and so glad you could join us tonight!"

The service came two days after William and Kate released a photo from their family's Christmas card. The event also took place on the same day the second part of Prince Harry and Meghan Markle's Netflix docuseries was released.

Harry & Meghan—which was produced in part by the couple's media company Archewell Productions—gives viewers glimpses into the Duke and Duchess of Sussex's life in California and covers what they say led to their decision to step back as senior members of the royal family in 2020. In one episode, Harry talked about a meeting he said he had with William, King Charles III and Queen Elizabeth II at Sandringham House after he and Meghan announced they were stepping back.

"It was terrifying to have my brother scream and shout at me and my father say things that just simply weren't true and my grandmother, you know, quietly sit there and take it all in," he said. "But you have to understand that from the family's perspective, especially from hers, there are ways of doing things, and her ultimate sort of mission goal/responsibility is the institution."

E! News has reached out to Buckingham Palace but has not received any comment.

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