Her Royal Highness has organised her customary Christmas carol concert at the historic Abbey, with a congregation comprising members of the royal family, famous faces, and community champions who have helped their communities.
The 1,600 guests will listen to a blend of carols, music and readings from actors such as Kate Winslet and Chiwetel Ejiofor.
The central message of the service, held in the atmospheric historic church on Friday afternoon, is generosity and expressing affection towards one's neighbour.
Among the guests will be Jonathan and Anna Cordiner, whose daughter died of a tumour, and who established a foundation, Kayleigh's Wee Stars, to support families who have a youngster facing a life-limiting condition.
"Your efforts, love, and understanding, often quietly and unspoken, and without any expectation or recognition, make an profound impact to the well-being of people," the Princess expressed in a note prior to the carol service.
The royal has been undertaking her own steady comeback to official duties following her health challenges and treatment, in November making her initial major address in two years, in which she discussed recognising the "selfless, commonly overlooked efforts of carers".
Guests arriving at the Abbey can listen to talented youth performers backed by the Future Talent charity, established in part by the former royal to increase availability of music lessons.
An 18-year-old named Carys Wood, who plays the trumpet and is from southwest Wales, has been supported by the trust, with funding assisting with instruments, tuition, and transportation expenses - and she said it was "awesome" to be taking part in tonight's service.
"Musical pursuits are frequently pricey," the musician remarked. She is now studying at the renowned conservatoire, and added that "all people deserve the chance" to develop their musical skills.
Eliza, Carys's sister who is 11, who performs on the brass instrument, will likewise attend the Abbey. "It's unbelievable that I get to perform here in front of so many notable figures," she said.
Among the guests will be people from various age groups.
That will encompass nine-year-old Saphia Turner, honouree of a youth community award, who creates and sells art and completes fundraising tasks to raise money for food banks.
The Abbey has been decorated with specially made wreaths, with TV cook Mary Berry and florist Simon Lycett assisting in their creation.
Taking to the stage will be recording artist Katie Melua, choristers from Westminster Abbey and a maritime folk band from Cornwall, the group Fisherman's Friends, who said the opportunity to perform was "the perfect culmination."
This annual carol service will be televised and shown on a major network on Christmas Eve.
A tech enthusiast and entrepreneur with over a decade of experience in driving digital innovation and business growth.
Billy Price
Billy Price
Billy Price
Billy Price