Britain's Queen Elizabeth II (C) smiles flanked by Prince Charles, Prince of Wales (L) and Prince Andrew, Duke of York (R), ahead of the fly-past on the balcony at Buckingham Palace following the Queen's Birthday parade, 'Trooping the Colour,' in central London on June 15, 2013. The ceremony of Trooping the Colour is believed to have first been performed during the reign of King Charles II. In 1748, it was decided that the parade would be used to mark the official birthday of the Sovereign. More than 600 guardsmen and cavalry make up the parade, a celebration of the Sovereign's official birthday, although the Queen's actual birthday is on 21 April. AFP PHOTO / CARL COURT (Photo credit should read CARL COURT/AFP/Getty Images)
