Prince George, Princess Charlotte, Prince Louis: See the royal grandchildren on coronation day

Their grandfather was the star of the show, but it didn't take much for the royal kids to steal the spotlight.

During the coronation of Britain's King Charles III on Saturday, all eyes were on his adorable and precocious grandchildren ? Prince George, 9, Princess Charlotte, 8, and Prince Louis, 5. Clad in elaborate garments as they sat through the long coronation ceremony, the young Windsors caught the eye of spectators and fans during the historic event.

George, a future king himself, served as one of King Charles' Pages of Honor. Carrying one corner of Charles' gilded robe, he walked in the procession with the king and Queen Consort Camilla into Westminster Abbey at the outset of the ceremony and stood behind the King during important moments inside the church. His younger siblings joined the procession into the Abbey and then took their places in the crowd along with their parents, Prince William and Princess Kate. At one point, Charlotte and Louis were photographed holding hands.

Everything that happened at King Charles III's coronation

See this matching moment: Princess Kate and Princess Charlotte's twin in McQueen at the coronation

Prince George wore red ceremonial garments signifying his official duties. Princess Charlotte wore an Alexander McQueen dress and cape in ivory silk crepe with ivory satin stitch embroidery featuring rose, thistle, daffodil and shamrock motifs, to signify the four nations of the United Kingdom, according to Buckingham Palace. Her sparkly headpiece is by Jess Collett x Alexander McQueen. Prince Louis wore an outfit made by Dege and Skinner, which consists of a Hainsworth garter and blue doeskin tunic with specially designed lace work embellishment to the collar, cuffs and fronts.

Prince Louis cracks up Twitter with coronation reactions

Prince Louis especially drew laughs on Twitter, where users shared photo and videos capturing the young royal's adorably unpredictable reactions to the coronation proceedings. At one point, Louis looked up and pointed at the sky while with his family on the balcony of Buckingham Palace, and at another point during the ceremony in Westminster Abbey he looked around before letting out a yawn.

The way Louis waved from the balcony at the end of the ceremony also garnered attention, with the young royal looking unamused while clapping his hands together.

When have the royal kids stolen the show before?

This isn't the first time that the royal kids have stolen the show at an official monarchy event. Whether it’s Prince George's comical excitement during the Platinum Jubilee Pageant, Princess Charlotte's solemn grace at the funeral of Queen Elizabeth II or Prince Louis' colorful facial expression at the Trooping the Colour parade, these monarchs-in-waiting know how to mark an occasion.

Tom Quinn, author of "Gilded Youth: A History of Growing Up in the Royal Family," says the youthfulness evoked by younger members of the royal family often serves as the “icing on the cake” at ceremonies such as the coronation.

"People love to see children at these things," Quinn tells USA TODAY. They "make people feel good about the whole thing, rather than all the focus being on people who are much older."

Prince Harry's children ? Prince Archie and Princess Lillibet, 1, ? were absent, along with their mother Duchess Meghan. (The day is also Archie's fourth birthday.) Ensuring the safety of his family remains a top priority for Prince Harry, who last February launched a legal challenge against the U.K. government's refusal to let him personally pay for police protection when he comes to Britain. Senior members of the royal family are given taxpayer-funded police protection, but Harry lost that perk when he and Duchess Meghan stepped down as senior working royals and moved to the U.S. in 2020.

His legal team said at the time that Harry wants to bring his children to visit his home country, but believed it would be too risky without police protection.

More: 'Not My King' protestors arrested during coronation of King Charles III

Contributing: Edward Segarra, Charles Trepany

Read all our King Charles coronation coverage:

Biggest moments: Charles and Camilla crowned, royal family appears on balcony

The balcony: See who greeted the crowd with Charles and Camilla (not Harry)

King Charles III formally crowned: A recap of the monarch's coronation day

Queen Camilla looks regal: She is also crowned at King Charles III coronation

Prince Harry: Royal attends but misses balcony palace moment

Prince George, Princess Charlotte, Prince Louis: See the royal grandchildren on coronation day

Prince Harry and Prince William: Look back their complicated relationship

Coronation photos: See all the best photos from the ceremony and procession

This article originally appeared on USA TODAY: Prince George, Princess Charlotte, Prince Louis: Coronation day photos