It marked her most important event since her cancer diagnosis, as the Princess of Wales was surrounded by her family at an event that has fast become a key component of her royal diary.
But if she felt any pressure from the significance of the occasion, it didn’t show as Kate simply flashed her trademark smile and got underway with the service as if the past year was a distant memory.
She delighted at meeting guests and stepping out alongside her husband and three children.
The challenging year clearly shaped the service, with themes of love, kindness and empathy shining through every element of it.
She has already spoken about how her nearest and dearest, particularly her husband of 13 years, helped her get through the demands of chemotherapy and last night’s service appeared to be a celebration and thanks to those who rallied around her.
But being the all-caring, all-loving Princess that she is, Kate wanted to extend her thanks to those who quietly help others on a daily basis, whether it be supporting family and friends or through work and volunteering.
Those invited have incredible stories to share, of raising money for charity, helping people through their darkest times and performing thankless acts for those in need – and Kate helped to shine a light on them.
The Carol service marks just her seventh public event this year, as both her doctors and aides have carefully constructed a gradual return to duties since her cancer treatment came to an end.
Kate knew all eyes would be on her tonight and she was surely buoyed by the large turnout from members of the Royal Family and her own family.
Her confidence and ability to lead an event so soon after completing her chemotherapy is a positive sign of things to come.
It’s been a busy week for the Princess, having attended the day elements of the Qatari state visit on Tuesday and overseeing the finishing touches of her Together At Christmas Carol Service.
Her next public appearance is expected to be on Christmas Day, when the royals will walk to St Mary Magdalene Church and greet well wishers gathered on the Sandringham Estate.
Kate is also hoping to attend the private pre-Christmas lunch at Windsor Castle with members of the extended Royal Family.
And we can expect her to continue to ramp up her public engagements from the New Year.
It will still be a cautious approach on advice of her doctor, but as William said last month, he very much hopes the pair will be able to undertake foreign trips together.