LONDON, UNITED KINGDOM - JULY 10: (EMBARGOED FOR PUBLICATION IN UK NEWSPAPERS UNTIL 48 HOURS AFTER CREATE DATE AND TIME) Prince William, Duke of Cambridge, Queen Elizabeth II and Prince Philip, Duke of Edinburgh watch a flypast of Spitfire & Hurricane aircraft from the balcony of Buckingham Palace to commemorate the 75th Anniversary of The Battle of Britain on July 10, 2015 in London, England. (Photo by Max Mumby/Indigo/Getty Images)