Beatrix (Beatrix Wilhelmina Armgard, born 31 January 1938) is the Queen regnant of the Kingdom of the Netherlands comprising the Netherlands, Curaçao, Sint Maarten, and Aruba. She is the oldest daughter of Queen Juliana of the Netherlands and Prince Bernhard of Lippe-Biesterfeld. She studied sociology at Leiden University. In 1966, she married Claus von Amsberg, with whom she had three children: Prince Willem-Alexander of the Netherlands, Prince Friso of Orange-Nassau and Prince Constantijn of the Netherlands. When her mother Juliana stepped down on the 30 April 1980, Beatrix succeeded her as Queen of the Netherlands.