Albert Speer, one of Hitler's confidants, wrote that Eva Braun would prove "a great disappointment to historians". She may disappoint historians, but the woman who was Frau Hitler for just 24 hours, before engaging in a joint suicide pact in 1945, has proved an enduring fascination for other writers. In the latest attempt to understand the mentality that attracted an ordinary young woman to the megalomaniac dictator, Martin Amis, in his novel The Zone of Interest, has volunteered the idea that the pair had sex without removing their clothes.
As a writer whose new novel also concerns Eva Braun, I can sympathise with the frustration that understanding her raises. How can a woman have a relationship with a man who is in many ways the embodiment of evil? Was she in denial, or simply self-deluding?
There is no more troubling way of viewing the Nazi leaders than in examining the women who loved them. Sometimes the personal lives of the senior men - their relationships with their wives and children - are more disturbing than pictures of their ranting speeches, because they force us to consider them as human beings.
Eva Braun met Hitler when she was a 17-year-old, convent-educated shop-girl working for Hitler's official photographer, and he was a 40?year-old aspiring politician. He had tickets to the opera, she accepted, and so began a tortured 12-year relationship that involved several suicide attempts and led Hitler's chauffeur, Eric Kempa, to label her "the unhappiest woman in Germany". From Eva's letters, we learn that her parents disapproved, and that Hitler would frequently ignore her in public, merely passing her an envelope of money at the end of the evening. When she was finally allotted a room in the Berlin Chancellery, she was forced to use a back entrance in case anyone saw her.
Hitler and his henchmen tried their hardest to keep Eva out of the spotlight, and forbade any picture of her to be published, because they were keen to project the idea that he was "married to Germany". Yet Eva herself ensured the opposite for posterity. She was an early adopter of cine-film and made endless home movies. Today she would have been constantly on Facebook, Instagramming her meals and taking selfies at the Berghof. One of her more astonishing ambitions was to star one day in a "bio-pic" of her life with the man she liked to call "Wolf".
Yet inevitably it is their sex life that has filled tomes, because in sex, we believe, a person's deepest essence is revealed. Rumours of homosexuality had dogged Hitler since the early Twenties, repeated in Munich newspapers and bolstered by his close relationship with Ernst Rohm, the homosexual head of the Sturmabteilung, the Nazi Party militia.
There is good reason to believe that he did have repressed homosexual tendencies, yet the dictator's interest in women is also well-attested. He would invite actresses back to his apartment for "private performances". One actress, Renata Muller, spread rumours about Hitler's alleged proclivity for self-abasement, with suggestions that he knelt at her feet and asked her to kick him. When she fell to her death from a window in 1937, many questioned the verdict of suicide.
Even more eye-catching was the secret 1943 report from America's Office of Strategic Services (forerunner of the CIA) which labelled Hitler an "impotent coprophile". Based on claims from Otto Strasser, one of Hitler's opponents in the Party, it alleged that the dictator forced his niece Geli to urinate and defecate on him. While it is hard to separate reality from politically inspired propaganda, Hitler's obsession with the unfortunate Geli was probably the deepest of his life, and her suicide in his apartment brought him close to breakdown. Geli, like Eva, did not threaten him intellectually. "There is surely nothing finer than to educate a young thing for oneself," he opined. "A lass of 18 or 20 years old is as pliable as wax."
It is impossible to peer behind the bedroom door, but Amis's speculation that Hitler was "sexually a void", because of his obsession with hygiene, is contradicted by observers at the time, who suggest that Hitler and Eva did share a bed as a couple. They had interconnecting bedrooms at the Berghof and Hitler's valet, Heinz Linge, attests that they would go to bed together.
While Hitler's maid, Pauline Kohler, wrote that "Hitler is not strongly sexed", Eva Braun's correspondence reveals nothing unusual - certainly not along the lines of fully clothed sex - except that once war had broken out, Hitler was unable to get interested. She used to show her friends a 1938 photograph of Neville Chamberlain on a sofa in Hitler's Munich flat, saying: "If only he knew what goings-on that sofa has seen!"
It would be surprising, as Amis says, that such a warped psychology as Hitler's could ever be "a considerate and energetic lover". Yet, once I began to write about the Nazi wives, I realised that the ability of mass murderers to compartmentalise their lives is one of their most disturbing aspects.
A new documentary about Himmler's home life, called The Decent One, by the acclaimed filmmaker Vanessa Lapa, focuses on the tender personal letters between Himmler and his wife Marga, largely about their daughter Puppi, even as he perpetrated daily atrocities. It raises the same questions as Thomas Harding's book Hanns and Rudolf, about the private life of Rudolf Hoss, the Auschwitz commandant, whose children played just yards away from the camp, oblivious of the horrors occurring there.
Looking at the women who loved the Nazis is not prurient. It matters because viewing the Nazi leaders on the human scale - as fathers, lovers and husbands - is what makes their activities more repellent than ever.