ZWOLLE, NETHERLANDS - APRIL 27:  King Willem-Alexander of The Netherlands, Princess Ariane of The Netherlands, Princess Alexia of The Netherlands, Crown Princess Catharina-Amalia and Queen Maxima of The Netherlands attend King's Day (Koningsdag), the celebration of the birthday of the Dutch King, on April 27, 2016 in Zwolle, Netherlands. Parties and concerts are held across the Netherlands as members of the Dutch royal family oversee festivities.  (Photo by Andreas Rentz/Getty Images)