Despite his categorical denials, irrefutable proof of the late prince Bernhard’s membership of the Nazi party NSDAP has been found in his private archives.

Flip Maarschalkerweerd, former director of the royal archives found the original membership card when making an inventory of the prince’s private papers some years before his retirement in 2019. Maarschalkerweerd makes the revelation in his book De Achterblijvers (Those who stayed behind) which is to be published on Wednesday.

Prince Bernhard had always denied he was a member of Hitler’s national socialist party, despite a copy of his membership discovered in the United States in the 1990s.  Letters discussing the termination of his membership in 1936, the year in which he became engaged to the then princess Juliana, have also been found.

“I swear on the bible: I was never a Nazi. I never paid party dues. I never had a membership card,” the prince told the Volkskrant in an interview published after his death. He did admit to having been an aspiring member of the Sturmabteilung (SA) and the Schutzstaffel (SS), ostensibly because he could not graduate unless he “participated a little”.

Maarschalkerweerd said he was surprised to find the card among the papers because they were part of a German file. But he also found a note dating from 1949 from army officer Lucius Clay who headed the American Zone in Germany who told him he had kept the document in his safe and would have destroyed it himself when it occurred to him “that you have earned the right to destroy it yourself”.

Maarschalkerweerd said he supposes the document had been found by the Americans and copied, which explained its later appearance in the US.

“For me personally this is good to hear,” historian Gerald Aalders, who discovered the copy, told the NRC. “I was accused of all sorts of things at the time. A week before he died Bernhard rang me to deny everything. He tried to deny what could not be denied.”

Aalders said he didn’t think the card was a fake, used by the Germans to blackmail Bernhard during the war. “There’s also the correspondence between his friends who had to make sure his membership was stopped. No, this is beyond any conspiracy theory,” Aalders told the paper.

Biographer Annejet van der Zijl, who uncovered Bernhard’s membership card of a Nazi-affiliated student association, said it would have been “illogical” if the prince had not been an NSDAP member.

Playboy

“A man of his background, a playboy, would not have had the insight that it might be better for him not to join. But the truth has slowly emerged and that is a feather in the cap for Maarschalkerweerd, as well as the royal family,” she said.

Maarschalkerweerd was given access to all documents relating to the war for a book about queen Wilhelmina’s exile in Great Britain by king Willem Alexander and only mentions the discovery of the membership card in a foot note.

The card and the correspondence will soon be put in the public domain as access to the royal private archives will be extended to September 6 1948 at the beginning of next year. It is currently restricted to the demise of queen Emma in 1934.