In addition, the Duke and Duchess of Cambridge decided to release an additional photograph taken from the day, and the public were never meant to see it.
An official statement read, 'The Duke and Duchess of Cambridge have released an additional photograph taken following the christening of Prince Louis.
'The Duke and Duchess hope that everyone enjoys this lovely photograph of Prince Louis as much as they do. 📷 @mattporteous'
The photo, a stunning candid of Kate and her two-month-old son laughing, was taken by photographer Matt Porteous.
According to The Mirror, Mr Porteous was commissioned to take photos of the family for their private collection, but when the family saw this shot - they couldn't help but share it.
Porteous has worked with the royal family before, photographing Prince George for his third birthday in 2016.
Want to know what REALLY went on at Prince Louis' royal christening. Listen to the latest instalment of New Idea Royals.