LONDON, ENGLAND - MAY 18: His Royal Highness Crown Prince Alexander II of Serbia and Crown Princess Katherine of the House Karadjordjevic attend a dinner for foreign Sovereigns to commemorate the Diamond Jubilee at Buckingham Palace on May 18, 2012 in London, England. Prince Charles, Prince of Wales and Camilla, Duchess of Cornwall hosted the event. (Photo by Samir Hussein/WireImage)