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 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.

Queen Camilla wore a sour expression during the Trooping the Colour Parade, which got many online users speculating about what had happened to her face.

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.

The parade travels from Buckingham Palace down The Mall to Horse Guards Parade. Then, following tradition, Charles, Queen Camilla, 77, and other work members of the royal family stoof on the Buckingham Palace balcony to watch a flypast. As the family headed back inside Buckingham Palace, Prince Louis turned and gave the crowd one final wave.

The young Princess attended the event alongside her family and paid tribute to her late great-grandmother along the way.

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.