Prince Louis has been christened.

Duchess Catherine and Prince Louis via Kensington Palace's Twitter video (c)

Duchess Catherine and Prince Louis via Kensington Palace's Twitter video (c)

The third child of Prince William and Catherine, Duchess of Cambridge - who also have four-year-old Prince George and three-year-old Princess Charlotte together - was born in April this year, and on Monday (09.07.18) members of the royal family gathered in a private ceremony at the Chapel Royal at St James' Palace in London to watch the tot's baptism.

Louis was baptised by the Archbishop of Canterbury, the Most Reverend Justin Welby in a 40 minute service which started at 4pm, and was attended by royals including William's brother Prince Harry and his new wife Meghan, Duchess of Sussex.

Catherine's father Michael Middleton, as well as her pregnant sister Pippa and her husband James Matthews, were also amongst those invited to the service.

Queen Elizabeth and her husband Prince Philip were not present at the ceremony, after it was decided "some time ago" that they would not attend for unknown reasons which are not thought to be health related.

Prince Louis wore the same christening gown as his siblings, which is a replica of the robe made for Queen Victoria's eldest daughter in 1841, which is now too delicate to be worn.

A video of Prince William and Duchess Catherine, both 36, and their brood entering the chapel was shared on the Kensington Palace Twitter account, which shows Catherine holding their youngest tot in her arms whilst he sleeps.

She was heard describing her son as "very relaxed and peaceful", and told the Archbishop with a smile: "I hope he stays like this."

Louis' baptism comes after it was recently revealed he will have no less than six godparents, who are all friends or family of Their Royal Highnesses.

The list includes Nicholas van Cutsem, former Etonian Harry Aubrey-Fletcher and Lady Laura Meade, who is the wife of royal wedding speech-maker James Meade.

Another well-known name to appear on the list of godparents includes Guy Pelly, who is the owner of the London nightclub Tonteria.

Elsewhere, Sophie Carter - who already acts as a godmother for three-year-old Princess Charlotte - is among the list, and so is Lucy Middleton, a cousin of the Duchess.