King Charles will attend the Christmas Day church service at Sandringham later for the first time as monarch.
The King and Camilla, the Queen Consort will be joined by the Prince and Princess of Wales on the royal estate in Norfolk.
They are expected to greet crowds gathering outside St Mary Magdalene Church following the service.
It will be the first time members of the Royal Family have spent Christmas at Sandringham House since 2019.
The royal standard is flying above the Sandringham House, marking a return to traditional royal festivities.
The Princess Royal and her family, and the Earl and Countess of Wessex and their children, are expected to join the King this Christmas. The Duke of York and his former wife, Sarah, Duchess of York, are also understood to be at the royal estate.
The only notable absentees are the Duke and Duchess of Sussex who last celebrated Christmas at Sandringham in 2018.
It will be the first year the King has hosted the Royal Family’s traditional gathering at the Norfolk estate since the death of his mother.
Queen Elizabeth II hosted 32 Christmases at Sandringham but was forced to cancel her annual festivities in 2020 and 2021 due to the Covid pandemic.
The King recorded his first Christmas broadcast on 13 December in St George’s Chapel at Windsor Castle, where the late Queen was buried in September.
Crowds have gathered outside St Mary Magdalene Church on the Norfolk estate to see the royals as they walk back to the house following the service. Some have brought Christmas gifts for the Royal Family.
Members of the public had been advised to arrive early to get a glimpse of the royals.
Norfolk Police said usual security and traffic control measures would be in place.
Sandringham House has been the private home of British monarchs for more than 160 years.