LUXEMBOURG - OCTOBER 20:  Princess Victoria of Sweden, Princess Mary of Denmark, Princess Mette Marit of Norway and Prince Haakon of Norway attend the wedding ceremony of Prince Guillaume Of Luxembourg and Princess Stephanie of Luxembourg at the Cathedral of our Lady of Luxembourg on October 20, 2012 in Luxembourg, Luxembourg. The 30-year-old hereditary Grand Duke of Luxembourg is the last hereditary Prince in Europe to get married, marrying his 28-year old Belgian Countess bride in a lavish 2-day ceremony.  (Photo by Sean Gallup/Getty Images)