Here's the first photo of Prince William and Kate Middleton with all three children

The Duke and Duchess of Cambridge had their very first public outing and photographs of their whole family taken on Monday. The occasion that made this possible was their last born Prince Louis’ christening.

The event was held at Chapel Royal at St. James’ Palace. Kensington Palace shared a video of Prince William and Duchess Kate arriving with their three children for the event.

Prince William, his wife Duchess Kate, their children Prince George, 4, and Princess Charlotte, 3, all came together for the christening of Prince Louis. This was the first time the whole family has been seen in public together.

In May, Louis was thought to be too young to attend Prince Harry and Duchess Meghan’s wedding. He was also still too young for Trooping the Colour

For more on this story go to our Twitter account @amomama_usa. His mother was seen carrying the sleeping boy in her arms as they arrived at St. James’ Palace.

Louis wore the Royal christening robe. It’s a replica of the 1841 gown made for Queen Victoria’s daughter Victoria, Princess Royal.

The original one was used for Royal baby christenings up until 2008. It was then deemed too fragile for future use causing the replica to be made.

Kate wore a white Alexander McQueen dress for the occasion. Her husband took charge of the older children as he held the hands of Prince George and Princess Charlotte.

The siblings greeted the Archbishop of Canterbury and Lord Chartres. “Charlotte, can you shake his hand?” William asked about both clergymen.

The princess obliged adorably, and her older brother did the same too. Inside the chapel, Louis was christened in the Lily Font.

The baptismal font was made for Queen Victoria and Prince Albert for their eldest daughter. It’s been used in every British Royal christening since then.

Water from the River Jordan was used to bless the child. The little Prince was surrounded by his six godparents, which included Prince William’s close friends Guy Pelly and Nicholas van Cutsem.

Kate’s cousin Lucy Middleton was also in attendance. After the ceremony ended the whole party had a slice of Prince William and Kate’s wedding cake.

The cake was served with tea more than seven years after it was first eaten at Buckingham Palace.