WINDSOR, UNITED KINGDOM - MAY 13: (EMBARGOED FOR PUBLICATION IN UK NEWSPAPERS UNTIL 48 HOURS AFTER CREATE DATE AND TIME) Prince Philip, Duke of Edinburgh and Gerald Grosvenor, Duke of Westminster attend the Royal Windsor Endurance Event on day 3 of the Royal Windsor Horse Show in Windsor Great Park on May 13, 2016 in Windsor, England. (Photo by Max Mumby/Indigo/Getty Images)
