Britain's Prince Charles, Prince of Wales on horseback follows Britain's Queen Elizabeth II in a horse-drawn carriage into Horseguards parade for the Queen's Birthday Parade, 'Trooping the Colour', in London on June 8, 2019. - The ceremony of Trooping the Colour is believed to have first been performed during the reign of King Charles II. Since 1748, the Trooping of the Colour has marked the official birthday of the British Sovereign. Over 1400 parading soldiers, almost 300 horses and 400 musicians take part in the event. (Photo by Daniel LEAL-OLIVAS / AFP)