The 178-year-old silver-leaf Lily Font, which forms part of the Crown Jewels, was brought from the nearby Tower of London especially for the occasion.
It was commissioned by Queen Victoria and designed by her husband, Albert, for their eldest daughter, Victoria, Princess Royal. The baby was christened in 1841 and the font has been a feature of royal christenings ever since.
It’s 43cm high and decorated with waterlilies and cherubs playing harps, and is usually on display in the Jewel House at the Tower of London.
As is tradition, Louis was baptised with holy water from the River Jordan, where Jesus was baptised by John the Baptist. The water is flown in from Israel especially for royal christenings.