The Duke and Duchess of Cambridge will present their son Prince George for baptism tomorrow afternoon at 3pm.
The couple have eschewed the traditional venue of the Music Room inside Buckingham Palace and in favour of the Chapel Royal inside St James's Palace.
The intimate venue will host 60 guests including The Queen, the Duke of Cambridge, the Prince of Wales and the Middletons, and other friends and family from both sides.
The couple both have an intimate connection with the historic chapel: It is where Kate received communion before her wedding back in April 2011.
It is also where the body of Diana, Princess of Wales, lay for her family and loved ones to pay their private respects before the very public funeral in Westminster Abbey in 1997.
The Chapels Royal historically refers to a body of priests and singers who served as the spiritual needs of royalty, but today it is associated with a number of chapels used by monarchs to worship.
The two main Chapels Royal are located at St James's Palace: The Chapel Royal and the Queen's chapel.
The first choir school was founded by King Sighbert of the East Angles in 635 AD, and in medieval days the clergy accompanied the royals on to the battlefields of Crecy and Agincourt.
Mary Tudor's heart was buried in the grounds of the chapel in 1558, after her beheading.
Thirty years later Elizabeth I prayed there for victory against the threat of the Spanish Armada.
Queen Victoria married her cousin Prince Albert of Saxe-Coburg and Gotha inside the Chapel Royal on February 10, 1840 an the couple celebrated their wedding breakfast at Buckingham Palace.
The chapel has long been considered the "cradle of English church music" and among its many noted composed and organists were Thomas Tallis, William Byrd and Henry Purcell.
Formal photos will be taken after the service and a historic picture will be released featuring the Queen with the three heirs to the British throne: Prince Charles, Prince William and Prince George.