It was a full-house for the royal family as the Prince and Princess of Wales were joined by all three of their children for Kate's Christmas concert at Westminster Abbey on Friday.
Prince George, ten, Princess Charlotte, eight, and for the first time, Prince Louis, five, accompanied their parents to the festive event in London.
Kate, 41, who arrived ahead of her family was greeted by loud cheers as she emerged from her car.
The royal looked beautiful in all-white ensemble, with a custom coat by Savile Row tailor Chris Kerr, high-waisted trousers from Holland Cooper and earrings from Van Cleef & Arpels.
Charlotte was dressed in one of her signature winter coats in burgundy, while Prince William, George and Louis looked smart in matching suits.
See the Princess of Wales's arrival in the clip below...
Ahead of the service, Kate met with some of the performers including Beverley Knight, Adam Lambert and Freya Ridings.
Family members in attendance at the soiree included the Duchess of Edinburgh, Princess Beatrice, Princess Eugenie, and Kate's parents, Carole and Michael Middleton, and her sister, Pippa Middleton.
While the King and Queen did not attend, Charles's cousin, Lady Sarah Chatto and her husband Daniel were among the guests.
The Abbey looked spectacular for the festive royal event. Christmas trees, provided by the King from Windsor Great Park and later donated to the local community, were decked with twinkling lights and paper and felt ornaments including holly leaves and miniature trees.
A Christmas Post Box was placed outside the West Door, for children to send handmade cards to other youngsters who might be struggling.
Princess Beatrice's stepson Christopher Woolf, known as Wolfie, was among the youngsters to post a card, along with George, Charlotte and Louis.
The cards, which the children had written themselves, were later distributed to charities including Evelina children’s hospital, British Red Cross, Child Bereavement UK, and East Anglia Children’s Hospice.
Beatrice looked festive in a blue and green tartan A-line dress from Beulah London, while her younger sister Eugenie opted for a sequined black coat with knee high boots.
William and Kate share a close bond with the Prince's cousin, Peter Phillips and Zara Tindall. Peter was joined by his daughters, Savannah, who turns 13 this month, and Isla, 11, whom he shares with his ex wife Autumn Kelly.
Zara's rugby star husband, Mike Tindall, remained at home with their three young children, Mia, nine, Lena, five, and two-year-old Lucas.
Kate's third carol service was in honour of all those who work to support babies, young children and families in communities across the UK and a celebration of the golden opportunity that the birth of a new baby brings.
Guests attending the service were nominated by Lord-Lieutenants across the nation and charities associated with the royal family and were recognised for their work to support children and families.
They included Noah Herniman, 17, from Chepstow, who has an inoperable brain tumour and has raised more than £35,000 to buy a caravan to offer families with a severely ill child a free holiday, and Jo and Chris Newby from Yorkshire, who have fostered more than 90 babies over the years and founded the Barton Inclusive Football club for disabled children and young people.
Jane Bell, a volunteer at Home Start West Berkshire, supports two young families each week and helps at the organisation’s baby bank, while Amanda Phillips from West Sussex set up Sparkles Food Parcels in her garden shed to help local families struggling to make ends meet.
Scout volunteer Andrew Taylor from Essex, who has worked tirelessly for the Scout Group in Great and Little Chesterford, Paula Pollitt, who has worked for Fortalice, Bolton Women’s Refuge, for 28 years and is a Children's Worker and foster carers Rhianne and Danny Parrot from the West Midlands were among those nominated.
Janet Holland, a devoted nursery worker from Derbyshire and Melissa Palmar, who set up Staffordshire Baby Bank, also attended.
Kate spoke with seven-year-old Oscar Burrow, from Lancaster, who when aged six climbed 12 mountains raising more than £40,000 for Derian House Children’s Hospice in Chorley, Lancashire.
His mother Kimberley Burrow said afterwards: "She said she’d heard about what he’s done and he’s doing a fantastic job, and hopes what he’s doing will inspire other children to do amazing things."
Among the highlights of the service were songwriter and multi-instrumentalist Jacob Collier playing last Christmas on John Lennon’s piano, which was owned by Wham! singer and solo-star George Michael and loaned by his estate.
Kate told Jacob that she and Princess Charlotte had been watching him play piano on YouTube.
"I said to Charlotte it takes a lot of practice. We saw you on YouTube," she told the musician, who confirmed afterwards that the future Queen had told him Charlotte was learning to play piano.
Broadcaster Roman Kemp, the son of Spandau Ballet bassist Martin Kemp and former Wham! backing singer Shirlie Kemp, introduced Jacob Collier and spoke about the role George Michael played in his life.
Oscar winning star Jim Broadbent also read an extract from Letters From Father Christmas by Lord of the Rings author JRR Tolkien. Chatting to the actor before the show, Kate told him: "Thank you for your time because I know the lead up to Christmas can be busy for people."
The service began with the popular carol, Once In Royal David’s City, and the congregation also heard a duet by Beverley Knight and Adam Lambert who performed The Christmas Song, made famous by Nat King Cole.
Meanwhile, William read the passage from the Gospel according to Luke that describes how Joseph and Mary travelled to Bethlehem to be registered and the birth of Jesus.
Ahead of the concert, a Kensington Palace spokesperson told HELLO!: "The Princess has been working hard behind the scenes to make sure this year’s Carol Service will be a moment to thank all those who work so hard to support babies, young children and families in our communities across the UK.
“Since launching her Shaping Us campaign in February she’s been shining a light on just how important the first five years are in a baby’s life.
"This year’s carol service will be a celebration of the golden opportunity that the birth of a new baby brings, and she can’t wait to welcome guests to the Abbey."
The event will be broadcast as part of Royal Carols: Together At Christmas, a special programme, airing on ITV1 and ITV X on Christmas Eve.
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