Britain's Queen Elizabeth II arrives in a horse-drawn carriage at Horse Guards Parade ahead of her birthday parade, called "Trooping the Colour", in London on Saturday, June 8, 2019. "Trooping the Colour" is the Queen's birthday parade and is one of the nation's iconic annual events. It is attended by almost every member of the royal family. [Photo: AFP]"

Members of the Welsh Guards, a regiment of the Household Division, march to the Horse Guards Parade ahead of the Queen's birthday parade, "Trooping the Colour", in London on Saturday, June 8, 2019. Over 1,400 soldiers, 300 horses, and 400 musicians took part in the event. The event has been held in celebration of the British sovereign's birthday for over 250 years. [Photo: AFP]"

Members of the Grenadier Guards line up in Horse Guards Parade for the Queen's birthday parade, "Trooping the Colour", in London on Saturday, June 8, 2019. [Photo: AFP]"

Meghan, Duchess of Sussex, and Prince Harry, Duke of Sussex, make their way in a horse-drawn carriage to Horse Guards Parade ahead of the Queen's birthday parade, "Trooping the Colour", in London on Saturday, June 8, 2019. [Photo: AFP]"

(L-R) Britain's Prince William, Duke of Cambridge holding Prince Louis, Prince George, Princess Charlotte, Britain's Catherine, Duchess of Cambridge, Britain's Camilla, Duchess of Cornwall, Britain's Prince Charles, Prince of Wales and Britain's Queen Elizabeth II stand with other members of the Royal Family on the balcony of Buckingham Palace to watch a fly-past of aircraft by the Royal Air Force, in London on June 8, 2019. [Photo: AFP]"