https://en.wikipedia.org/wiki/Prince_Bernhard_of_Lippe-Biesterfeld

While at university, Bernhard joined the Nazi Party. He also enrolled in the Sturmabteilung (SA), which he left in December 1934 when he graduated and went to work for IG Farben. The Prince later denied that he had belonged to SA, to the Reiter-SS (SS Cavalry Corps), and to the NSKK, but these are well-documented memberships. While he was not a fierce champion of democracy, the Prince was never known to hold any radical political views or express any racist sentiments, although he admitted that he briefly had sympathised with Adolf Hitler's regime.

Prince Bernhard was a member of the "Reiter-SS", a mounted unit of the SS and had joined the Nazi party before the war. He later also joined the National Socialist Motor Corps. Various members of his family and friends were aligned with the Nazis prior to the Second World War, and a number of them attended the royal wedding. Protocol demanded that the prospective Prince-Consort be invited to an audience with his head of state, who at the time was Adolf Hitler. Hitler gave an account of the conversation he had with Bernhard in his Tischgespräche (Table Conversations). This book was a collection of monologues, remarks, and speeches Hitler gave during lunch or dinner to those he had invited. The Prince's brother, Prince Aschwin of Lippe-Biesterfeld, was an officer in the German Army. Although the secret services on both sides were interested in this peculiar pair of brothers, no improper contacts or leaks of information were ever discovered. He cut off relations with those members of his family who were enthusiastic Nazis. As a sign of his "Dutchness", near the end of the war, he spoke only Dutch when negotiating the surrender of German forces in the Netherlands.