LONDON, ENGLAND - JUNE 13:   Camilla, Duchess of Cornwall on the balcony of Buckingham Palace during the Trooping the Colour Ceremony on June 13, 2015 in London, England. . The ceremony is Queen Elizabeth II's annual birthday parade and dates back to the time of Charles II in the 17th Century when the Colours of a regiment were used as a rallying point in battle.  (Photo by Chris Jackson/Getty Images)