Baudouin I, (1930–1993), the fifth king of the Belgians, the eldest son of Leopold III and Queen Astrid. He assumed the throne in 1951 after his father abdicated. Baudouin was born in Brussels and became heir apparent when his father succeeded to the throne in 1934. He and his family were interned by the Nazis during World War II. They lived in exile in Switzerland, 1945–50, because of opposition to his father by Belgian political leaders. The royal family returned in 1950, and soon after Baudouin was given the powers of king and the title of Prince Royal of Belgium. Leopold remained king in name only.