Prince George served as one of the eight Pages of Honour for grandfather King Charles III's coronation on May 6.
Prince Louis and Princess Charlotte held hands at the crowning ceremony.
Kate Middleton and Prince William accompanied their kids inside the Westminster Abbey in London.
Louis pointed something out to his younger sister at the church.
In true Lous fashion, the prince made one of his silly faces while riding in the family carriage.
Kate and William's youngest child was a total mood on this rainy London day.
George stuck his tongue out while standing in line with his fellow pages.
Louis adorably tried to get his mom's attention.
Charlotte sat close to Kate.
Charlotte and Louis looked out from the windows of their carriage as they rode to Westminster Abbey.
Inside the arriage, Louis yawned as his older brother George scratched his nose.
The family sat in the front row.
Charlotte and Louis followed their mom and dad in the procession.
For the occasion, Charlotte wore an outfit designed by Alexander McQueen.
Louis let out a small yan during the ceremony.
Despite being known for his cheekiness, Louis was largely on his best behavior.
George took his duties as a Page of Honour very seriously.
Little Louis looked dapper in a navy blue ensemble.
Charlotte rocked a silver bullion and crystal flower crown similar to Kate's Alexander McQueen headpiece.
Louis and Kate shared a sweet moment together during a break in the ceremony.
Kate escorted Charlotte and Louis out of Westminster Abbey following the coronation.
The siblings sat in a carriage behind their grandparents' Gold State Coach.
Louis flashed a smile from the cart.