Known as "Prins Claus" in the Netherlands, he was born in Dötzingen (Hitzacker), as Claus George Willem Otto Frederik Geert jonkheer von Amsberg. His father, a farmer, operated a farm in Tanzania from 1928 until World War II. Claus and his six sisters grew up at their grandparents' manor in Lower Saxony. Claus also attended a boarding school in Tanzania from 1936 to 1938. He was also a member of Nazi youth organisations such as Jungvolk and Hitlerjugend (said to be automatic for all members of his generation).
In 1944, he was conscripted to the German Wehrmacht. He became a member of the 90th Armored Infantry Division (90. Panzergrenadier Division) in Italy in March 1945, but was taken as a prisoner of war by the USA at Merano before taking part in any fighting.
After his release, he finished school in Lüneburg and studied law in Hamburg. He joined the German diplomatic corps and worked in Santo Domingo and Côte d'Ivoire. In the 1960s he was transferred to Bonn.
Claus and Beatrix met at the wedding-eve party of Princess Tatjana Wittgenstein and Prince Moritz of Hesse in the summer of 1964. Part of the Netherlands public was not very happy that Beatrix' fiancé was a German, only 20 years after the end of the war, and there were protests during the wedding celebrations. The two married on March 10, 1966.
Over time, Claus became accepted by the public, even so much that in the last part of his life he was generally considered the most popular member of the royal family. Reasons for this change in Dutch opinion were his strong motivation to contribute to public causes, especially third world development (on which he was considered an expert), his sincere modesty, his candidness (within, but sometimes on the edge of, royal protocol), and his approachability to all layers of society.
The public also sympathized with Claus for his efforts to give meaning to his life beyond the restrictions that Dutch law posed on freedom of speech and action for the royal family (lest they get involved in political controversy). Many also believed that these restrictions were at least partly the cause of his severe depression, which lasted many years. As a result, restrictions were loosened; Claus was even appointed as senior staff member at the Department of Developing Aid, albeit in an advisory role.
A fine example of his mildly rebellious attitude toward protocol was the "Declaration of the Tie". After presenting the annual Claus Award to three African fashion designers, Claus told "workers of all nations to unite and cast away the new shackles they have voluntarily cast upon themselves", meaning the necktie, that "snake around my neck", and encouraged the audience to "venture into open-collar paradise". Then Claus removed his tie and threw in to the ground.
Claus and Beatrix had three children: