Prince Louis' christening: all the best photos

The Duke and Duchess of Cambridge celebrated baby Prince Louis' christening on Monday, and what a beautiful day it was for it! The sun shone brightly as the royal family arrived for the afternoon ceremony at The Chapel Royal at St James's Palace - with the Duke and Duchess of Sussex and Prince Charles and the Duchess of Cornwall among the royal guests in attendance.

Notably absent, however, were Louis' great-grandparents the Queen and Prince Phillip, who were travelling back to London from Norfolk on the day of the service - at the start of what will be a very busy week of high-profile events.

From Kate's side of the family, doting grandparents Carole and Michael Middleton were also in attendance for the celebration, alongside a pregnant Pippa Middleton and her husband James Matthews, as well as youngest Middleton sibling James.

Earlier in the day, the royal couple confirmed that they'd chosen Nicholas van Cutsem, Guy Pelly, Harry Aubrey-Fletcher, Lady Laura Meade, Mrs Robert Carter (nee Hannah Gillingham) and Lucy Middleton as godparents to baby Louis. Click through the gallery to see the sweetest moments from the day… 

Duchess Kate arrived holding baby Louis, as her husband Prince William held hands with little Prince George and Princess Charlotte ahead of her. She then stopped to have a chat with the Reverend Justin Welby, as the new Prince slept soundly in her arms.

The Archbishop of Canterbury, Justin Welby, chats to a smiling Kate as she holds baby Louis before entering the chapel for the christening.

Prince George and Princess Charlotte looked very grown-up as they arrived hand-in-hand with dad William! Charlotte looked adorable in a sweet blue dress, while George was smart in a polo shirt and shorts - both outfits look very similar to those they wore to 2018's Trooping the Colour!

Mum-of-three Catherine looked absolutely thrilled to be celebrating the christening of her youngest. She wore a stunning cream dress by Alexander McQueen, and a matching hairband-style hat by Alice Taylor.

What a beautiful shot of mother and son, Kate and Louis! The baby Prince Louis wore a handmade replica of the Royal Christening Robe - made by Angela Kelly, dressmaker to the Queen.

Another lovely family shot of the Cambridges - Louis' christening marks their first outing as a family of five! 

Duchess Meghan looked gorgeous in an olive green Ralph Lauren midi dress, with her signature favourite bateau neckline and swept-back hairstyle. Prince Harry, meanwhile, looked dapper in a navy suit.

One of Louis' godfathers, Guy Pelly, and his wife Lizzy arrive for the service.

The Duchess of Cambridge's cousin Lucy Middleton, Hannah and Robert Carter and Harry Aubrey-Fletcher (back) arriving for the christening of Prince Louis.

Proud grandparents Carole and Michael Middleton were some of the first guests to arrive, followed closely by daughter Pippa and her husband James.

Kate and Pippa's younger brother James Middleton was also in attendance, of course, looking smart in a three-piece navy suit as he arrived with Lady Laura Marsham.

Pippa looked classic and elegant in a pale blue midi dress by Alessandra Rich, with a pleated skirt and a matching hat. 

Her growing baby bump was barely noticeable in the structured dress, which she accessorised with a box clutch bag, too.

William was busy taking care of George and Charlotte as the family left the church, while mum Kate cradled Louis!

Another shot of Meghan in her head-to-toe olive green outfit. Her matching hat, in her favourite disc style, was by Stephen Jones.

Prince Charles and the Duchess of Cornwall arrived just ahead of Kate and William. Camilla wore an elegant cream dress by Fiona Clare, and a straw-coloured hat by Locke. 

Prince Louis was impeccably behaved throughout, sleeping soundly in his mother's arms! Kate was heard describing her sleeping boy as "very relaxed and peaceful", adding with a smile: "I hope he stays like this."

Princess Charlotte, three, looked adorable in her blue floral frock with matching hairband, clutching the order of service as she left the chapel with dad William.