They may be young, but Prince George and Princess Charlotte are already old hats at this royal wedding thing.
The cheeky brother and sister have arrived at the wedding of Princess Eugenie and Jack Brooksbank and are once again taking centre stage as pageboy and bridesmaid respectively.
Dressed in white, George and Charlotte waved to the crowds and showed just how natural they were.
The two eldest Cambridge children weren't the only sweet faces in the bridal party.
Fellow bridesmaids Savannah Phillips, seven, Teddy Rose Williams (daughter of British popstar Robbie Williams and Ayda Field), five, Mia Tindall, four, and Maud Windsor, four, looked equally angelic in their bridesmaid dresses while six-year-old pageboy, Louis de Givenchy kept George company.
Lady Louise Windsor was also on hand to help the little ones into the church and was a vision dressed in royal blue, the same colour as Princess Beatrice, who is acting as maid of honour.
Little Prince Louis who was born in April was, of course, not old enough to attend the wedding, but George and Charlotte are seasoned pros.
The young prince and princess stood on the steps of St George's Chapel just a few months ago when they accompanied the former Meghan Markle down the aisle when she married Prince Harry.
The fourth and fifth in line to the throne also accompanied family friend Sophie Carter down the aisle in September and judging by the photos, they had a ball.
Plus, we can't forget their cheeky antics at their aunty's 2016 wedding when Pippa Middleton wed James Matthews.
There are plenty of British royal wedding traditions but one unofficial one is that the bridal party is reserved for children.
Like Duchess Catherine, who was famously accompanied by her sister Pippa on her big day, Princess Eugenie has enlisted the assistance of her big sister Princess Beatrice. The two sisters are famously close and it was revealed that Beatrice would take on the role as maid of honour in British Vogue.
Get to know Princess Eugenie in the video below.
All images: Getty/REX