Kate Middleton and Prince William joined the rest of the British royal family for the traditional Trooping the Colour festivities on Saturday. Prince Harry was also there, riding in a carriage alongside Kate before they shared laughs on the balcony with William. The queen's celebrations also included Prince Philip; Prince Charles; Princess Eugenie; Sophie, Countess of Wessex; Prince Edward; and Camilla, Duchess of Cornwall. Trooping the Colour is one of the British royal family's many traditions. It dates back to 1748, when the ceremony was deemed the official birthday celebration for the British sovereign. This year, following tradition, the royal family joined troops from the Household Division for a military ceremony. After the march, they returned to Buckingham Palace to greet huge crowds and watch the Royal Air Force fly overhead from the balcony. See all the best pictures from this year's Trooping the Colour below.