Sweden's King Carl XVI Gustaf and Queen Silvia arrive at the Nordic Museum in Stockholm on April 29, 2016 for a concert performed by the Royal Opera and the Stockholm Concert Hall to celebrate the king's 70th birthday.
Prince Alexander is the first child of Sweden's Prince Carl Philip and Princess Sofia.
King Felipe VI and Queen Letizia of Spain attend the Cervantes Prize award ceremony on April 23, 2016 in Alcalá de Henares, Spain.
King Willem-Alexander of the Netherlands (right) welcomes Indonesian president Joko Widodo at Noordeinde Palace in The Hague on April 22, 2016.
King Felipe VI of Spain (right) receives Prince Albert II of Monaco at the Zarzuela Palace in Madrid on April 22, 2016.
Indonesian president Joko Widodo (left) shakes hands with Belgium's King Philippe at the Royal Palace of Brussels on April 21, 2016.