Four official images were taken by British photographer Matt Holyoak at Clarence House after Louis was baptised in The Chapel Royal at St James's Palace a week ago.

The photographs have been released by the Duke and Duchess of Cambridge to mark the milestone.

In one photo, Kate and William are joined by their children, along with the Duke and Duchess of Sussex, the Prince of Wales and the Duchess of Cornwall, and the Middleton family including Kate's sister Pippa Matthews and her husband James.

Members of the royal family appear in another photo without the Middletons, a third photo features the Cambridge five, and the fourth photo is an image of just Kate and Louis.

The photographs were taken in the morning room and garden at Clarence House.

Louis was sound asleep as he was carried into the Chapel Royal by Kate for the christening ceremony, which lasted 40 minutes.

After the ceremony, the baby prince looked content and wiggled his fingers as Kate gazed down and beamed at him as she held him in her arms.

With Prince George and Princess Charlotte joining their parents for Louis' big day, it was the first time the Cambridges were seen together as a family of five.

Holyoak has worked with a host of celebrities and his photos have regularly been splashed on the covers of magazines such as Harper's Bazaar, Shortlist and Dazed and Confused.

He is not new to working with the royals, as he photographed the Queen and the Duke of Edinburgh as part of a series of portraits released to mark their 70th wedding anniversary.

Australian Associated Press