Prince Louis captured the nation's heart this evening as he made his debut alongside a star-studded crowd at the Princess of Wales' annual carol concert at Westminster Abbey.
Fans went wild as an adorable clip showed the young king's eyes lighting up as 74-year-old actor Jim Broadbent read JRR Tolkien's Christmas Letters.
The five-year-old, who was said to have “Christmas magic in his eyes,” was seen nudging his mother Kate, whispering “mama” and pointing at the award-winning star as he read to the audience.
When the youngest child of the Prince and Princess of Wales entered the concert, he and his older siblings, Princess Charlotte, 8, and Prince George, 10, sent letters to children who were less well off than him.
The trio stood proudly alongside their parents – and other senior royals – as they held candles and sang Christmas carols in the 1,500-person festive hall.
Prince Louis pointed and smiled as actor Jim Broadbent performed JRR Tolkien's Christmas Letters
At the start of the show, which aired on ITV tonight, the young prince was seen sending letters to the North Pole alongside his siblings
The Together At Christmas service, supported by the Royal Foundation, was held this year to honor those working to support babies, young children and families across the UK
The Together At Christmas service, supported by the Royal Foundation, was held this year to honor those working to support babies, young children and families across the UK.
In conjunction with Kate's Shaping Us campaign, the service will showcase “the hope for a new life and why it is so important to build a supportive and nurturing world around children and the adults in their lives.”
While it was filmed on December 8th, the full concert was broadcast to the public on ITV this evening.
Prince Louis was previously too young to attend his mother's annual Christmas concert, but his debut did not disappoint.
One wrote on social media: “Look how excited Prince Louis was to see Jim Broadbent, it was beautiful.”
Another said: “My favorite part of the whole service was Prince Louis' adorable reactions. 'He's so sweet.'
A third added: “He's a beautiful five year old with an enchanted Christmas smile.”
At the end of Broadbent's reading, Prince William and Prince George also exchanged smiles as festive cheer spread throughout the chapel.
In another adorable moment from the concert, captured on camera earlier this month, the teenager was seen cheekily blowing out his sister's candle at the concert – leaving his siblings stitched up in the process.
The mischievous royal blew out Charlotte's candle as her mother Kate laughed. In the picture, he was puffing out his cheeks as he tried to put out his older sister's candle while she smiled.
Prince Louis cheekily blew out his sister's candle at Kate's Christmas carol concert, sending his royal siblings into an uproar
Prince George, Princess Charlotte and Prince Louis walk with candles in Westminster Abbey
Prince Louis wore a checked shirt, a chic navy coat and Chelsea boots
Prince William also attended the service and read from the Gospel of Luke
The Welsh children were on their best behavior as they greeted the clergy at the Abbey's Lady Chapel.
Prince Louis appeared shy while his older brother and sister smiled, shook hands and said hello to the priest.
George looked like his father's doppelganger in a sharp suit, while his younger brother wore a navy button-up jacket, slim-leg trousers and blue suede Chelsea boots.
Charlotte, meanwhile, wore a £180 double-breasted burgundy wool coat from Trotters.
To open the ceremony, the Princess of Wales, dressed in a monochrome outfit, welcomed the audience watching from home on Christmas Eve to rewatch the service and spoke about the meaning of Christmas.
“Christmas is a time when we come together and celebrate the birth of a newborn,” she said.
“The birth of each baby is a precious and meaningful time, bringing us together to reflect on new beginnings and bringing hope for the future.”
“During our earliest interactions, relationships and experiences with those who love us, even before we are born, we lay the foundation for so much on which this future will depend.”
“But only by valuing and supporting the crucial role of adults in a child’s world can we hope to make a difference.”
The Princess of Wales and Princess Charlotte (left) smile as Prince Louis (centre) watches the Christmas service recorded earlier this month
The Princess of Wales' sister Pippa Matthews (left) and her husband James attend the service
Prince William also attended the service and read from the Gospel of Luke.
Sophie, Duchess of Edinburgh was pictured alongside the family of five.
Princess Beatrice, her stepson Christopher Mapelli Mozzi and husband Edoardo Mapelli Mozzi were also seen, as were Princess Eugenie, Zara Tindall and Peter Phillips and his daughters Savannah and Isla.
Although the King and Queen Camilla were not present at the event, they donated Christmas trees from Windsor Great Park to decorate Westminster Abbey, which were donated to the local community after the service.
The group of celebrities who greeted the family included singers Beverley Knight, Adam Lambert and musician Jacob Collier.
Kate's sister Pippa and husband James Matthews were seen at the event, as were Lady Sarah Chatto and her husband Daniel Chatto.
Midwives, kindergarten teachers and baby bank volunteers were among the 1,500 people invited to the festive event where they thanked those who work to support children in their early years.