Royal babies usually receive an official christening ceremony after their birth, which is performed by the Head of the Church of England.
Every royal baby is christened with water from the River Jordan, where it is said Jesus was baptized by John the Baptist.
The baby will be expected to wear the traditional royal christening gown, a replica of a gown made in 1841 for Queen Victoria's children. The original, made by Janet Sutherland, was worn by 62 royal babies.
The replica, made in 2004, has been worn by the Duke and Duchess of Cambridge's children, and more recently, baby Archie at his christening in July 2019.
It is unclear whether the couple will go ahead with an official royal ceremony. It is likely dependent on whether they can travel from California, where they currently reside, to the UK after the birth.