The only daughter of Prince William and Princess Kate coordinated with her mom in an aqua color for King Charles' birthday affair Trooping the Colour.

After arriving at Buckingham Palace by car, Kate and the children, Prince George, 11, Princess Charlotte and Prince Louis, 7, traveled in a traditional horse-drawn carriage down The Mall. Charlotte sat beside her mother, while her brothers faced backward across from them.

Kate Middleton and royal family unite at King Charles III's birthday parade, with the Princess of Wales wearing an ensemble reminiscent of late mother-in-law Princess Diana.

Kate Middleton is joining King Charles and Queen Camilla in a significant position at Trooping the Color. Why Princess Kate is with the King at Horse Guards Parade.

One of the most meaningful moments of Trooping the Colour happens at the finish when members of the royal family appear on the Buckingham Palace balcony to watch the RAF flypast, which every year, concludes the proceedings.

Ahead of Saturday's festivities, King Charles III also honored a handful of celebrities and public figures, including David Beckham, Gary Oldman and Elaine Paige.

Senior working royals including Prince William, Kate Middleton, Princess Anne, Prince Edward and Queen Camilla will reportedly take part in the king's birthday parade.

The Royal Family assembled on the Buckingham Palace balcony following the Trooping the Colour parade marking King Charles III's official birthday. The monarch and Queen Camilla took centre stage as they awaited an aerial display featuring the Red Arrows,