Every Photo You Need to See of Prince George and Princess Charlotte at Princess Eugenie's Wedding

Prince Edward's teenage daughter, Lady Louise Windsor, keeps Prince George, 5, and Princess Charlotte, 3, in line.

George sits ahead of his little sis.

Charlotte gives another of her signature waves on approach to the chapel.

Prince George makes his way up the chapel steps.

George and Charlotte, along with the other young members of the bridal party, wear looks by Amaia Arrieta of Amaia Kids. The design incorporates the Mark Bradford artwork included in the Order of Service.

Another "hello" from Charlotte, who handles the blustering winds like a pro.

The little ones have some fun on their walk down the aisle. In addition to George and Charlotte, the bridal party includes their cousins: 4-year-old Mia Tindall; Savannah, 7, and Isla Phillips, 6; and 5-year old Maud Windsor. Non-family includes Theodora Williams, 6, the daughter of British singer Robbie Williams and his wife Ayda Field, and Louis De Givenchy, 6, the son of Zoe and Olivier De Givenchy.

The bridesmaids make their way into the ceremony.

Why do royal children behave so well during weddings? As Myka Meier of Beaumont Etiquette, which was founded in Kensington and teaches courses on etiquette at The Plaza Hotel in New York City, told PEOPLE following Prince Harry and Meghan Markle's wedding, it's a result of practice, practice, practice.

The children follow the bride and her father, Prince Andrew, up the aisle.

George covers up his mouth in a funny candid moment.

As with Harry and Meghan's wedding, the children stay in a room to the side during the ceremony, returning to escort the bride and groom back down the aisle after they sign the marriage register.

George and Charlotte bring up the rear.

Could they be any cuter?

The bridesmaids' flowers are by Rob Van Helden and reflect the design of the bridal bouquet, featuring posies of Lily of the Valley and spray roses.

Following the newlyweds' first kiss, the attendants follow them down the 20 chapel steps.

No missteps here!

Another windy wave from Charlotte, a wedding party pro.

The kids on their best behavior, with the family of the bride — from left, Sarah Ferguson, Duchess of York, Princess Beatrice and Prince Andrew, plus the groom's mother, Nicola.

Everyone say "cheese!"

George shows off his serious side.