Angela Marie "Geli" Raubal was born in Linz, in what was then Austria-Hungary, on June 4, 1908. She was one of three children born to Leo Raubal Sr. and his wife Angela, and she grew up alongside her siblings Leo Jr. and Friedl.
Leo Sr. died in 1910, when Geli was just two years old. After the end of World War I in 1918, Angela moved with her family to Vienna.
A report by the Office of Strategic Services, a US intelligence agency during the Second World War, described Angela, Adolf Hitler's half-sister, as "rather a decent and industrious person." She became the manager of a boarding house for Jewish students and was often vocal about her dislike of anti-Semitic rhetoric.
Walter Langer, who wrote the report, noted that some informants who knew her during this time said that during student riots Angela defended the Jewish students from attack. On several occasions, she reportedly beat Aryan students away from the steps of the dining hall with a club.
In 1919, Hitler reached out to his sister, who had not heard from him in years. She visited him in 1924, and in 1925 Angela and Geli, then 17, moved after Angela was offered a position as her brother's housekeeper.
By all accounts, Hitler subsequently took a liking to Geli, despite the 19-year age gap and the fact that she was his niece. Notably, Hitler's own parents had been first cousins, so perhaps it did not seem abnormal to him to have such feelings about a blood relative.
He was also known to prefer young girls who were still in their teens, describing them as being malleable as wax so that a man could stamp his own imprint on her.
But Hitler was not the only one to notice that there was something magnetic and charming about teenage Geli. Seemingly lots of people did.
Frau Braun, a woman who lived in the same apartment building as Geli's family in the 1920s, recalled hearing her singing in the street outside. She described Geli as so tall and beautiful that she was speechless, and said Geli asked her if she was frightened of her.
Hitler was known to Geli as Uncle Alf. Writer Jesse Stevens observed that maybe the pair's relationship began with the older man acting as a father figure to the young girl who did not have one.
Hitler told his chief economic adviser Wagener that he could sit next to young women who left him completely cold, or who actually irritated him. But with a girl like Geli, he said, he became cheerful and bright, and after listening for an hour to her perhaps silly chatter he was free of all weariness and listlessness.
He told another confidant, his personal photographer Heinrich Hoffmann, that he was so concerned about Geli's future that he felt he had to watch over her. He said he loved Geli and could marry her, but that he wanted to remain single so he retained the right to exert an influence on her circle of friends until such a time as she found the right man.
According to witnesses, it was not a one-sided interest. Another of the future Führer's housekeepers claimed that Geli loved Hitler and was always running after him.
The pair were often seen enjoying meals at restaurants and shows at theaters, and Hitler even took his niece with him to meetings. He seemed to think this would impress his fellow Nazi Party members, saying their wives or girlfriends all looked like washerwomen.
But as previously stated, Hitler had no intentions of marrying Geli. He believed that he needed to be seen as single to boost his popularity among women, while at other times he claimed that he never married because he "wouldn't have been able to give enough time to my wife."
In 1928, three years after Hitler had first met Geli, he offered his mother a different position as a housekeeper at the Berghof, his holiday home at Obersalzberg. The following year, Geli moved into Hitler's Munich apartment after enrolling at Ludwig Maximilian University, where she studied medicine.
It is unclear, however, if Geli had a choice in whether or not she stayed with her uncle, and their relationship was reportedly turbulent, with both of them exhibiting signs of rampant jealousy.
Geli resented the fact that her uncle was entertaining 17-year-old Eva Braun by taking her out for rides in his car, while Hitler took great issue with Geli's flirtatious nature.
For the two years that Geli lived under his roof, she was subjected to Hitler's controlling and domineering nature, which effectively made her a prisoner. This was especially true after Hitler discovered that in 1927 she was romantically involved with his chauffeur, Emil Maurice.
Henrietta Hoffmann, the daughter of Hitler's photographer, claimed that Geli had told her she much preferred her relationship with Emil. Geli reportedly said that being loved is boring, but to love a man is what life is about, and when you can love and be loved at the same time it is paradise.
Geli had already agreed to marry Emil when Hitler found out about the relationship, forced them to end things, and fired the chauffeur. After this, Geli's socializing was drastically reduced, and she was often only allowed out in the company of Hitler himself or his most trusted confidants.
Despite the purported jealousy and the fact that the pair lived together, the exact nature of the relationship between Geli and Hitler is often debated. Historians today largely agree that the older man had a romantic obsession when it came to his niece, but they often argue about whether or not the relationship was a sexual one.
Some of Hitler's confidants believed that it was. Ernst Hanfstaengl, a businessman and close friend of the Führer, observed that Geli was willing to submit to his particular tastes. He added that she was the one woman in his life who went some ways towards curing his impotence and half making a man out of him.
However, others who were once close to the Führer believed that Geli had become uninterested in her uncle because of his unusual tastes. A film actress who had been intimate with Hitler told her director, before reportedly committing suicide, that she had been distressed by the kind of things he had required of her.
She claimed that he had collapsed to the floor and begged her to kick him until she finally gave in. SA officer Wilhelm Stocker commented that Geli admitted to him at times that Hitler made her do things in the privacy of her room that sickened her.
He added that when he asked her why she had not refused, she replied that she did not want to lose him to some woman that would do what he wanted. Meanwhile, early Nazi Party member Otto Strasser, who later became a political opponent of Hitler's, was aware that his jealousy was not the worst thing.
Strasser said Hitler demanded things from her that were simply disgusting, and that she had never dreamed such things could happen. When he asked her to tell him, she described things he had previously encountered in his reading of Krafft-Ebing's Psychopathia Sexualis when he was a student.
According to Strasser, who was told by Geli, part of Hitler's interests involved being urinated on. Historian Ian Kershaw believes that whether or not the pair were in a sexual relationship, Hitler's behavior towards Geli had all the traits of a strong sexual dependence.
The longer Geli remained a prisoner in Hitler's house, the more distressed she became and the more she resented her uncle. He had reportedly given her permission to go to Vienna and carry on with some singing lessons she had been taking, but he soon rescinded this decision and determined that she was not allowed to go, which greatly upset Geli.
For all the debate about the nature of the pair's relationship, one of Hitler's nephews stated that by the time of Geli's death in 1931, the family was aware that the two had long been intimate and knew that she was expecting.
Furthermore, another nephew claimed that he had been told by one of the housekeepers that Hitler and Geli argued about the trip to Vienna shortly before her death. When pressed about why she wanted to go, Geli told her uncle that she was pregnant.
It was never established whether or not Geli was expecting at the time of her death, as an autopsy was never performed.
Hitler last spoke to his niece on September 18, 1931, when he told her she would not be going to Vienna. He subsequently left for a meeting in Nuremberg but was contacted the following day when 23-year-old Geli was found dead in the apartment.
She had died from a gunshot wound to the lung. At the time of her demise, Hitler was on the brink of power, and news of a woman found dead in his home would of course not work in his favor, especially when it emerged that Hitler's gun, a Walther pistol, was found at the scene.
But he need not have been worried, because almost immediately damage control was being carried out on his behalf. His team claimed that the young woman had taken her own life due to nerves about an upcoming music recital.
Still, rumors began to emerge that she had been subject to physical abuse, and questions arose about the nature of the pair's relationship. There were even whisperings that Hitler had murdered his niece, and reports stated that the 23-year-old had been injured and her nose bone shattered before death.
Hitler's allies continued trying to dampen the story. A brief examination of the body was conducted by a police doctor, after which it was hastily determined that suicide was the cause of death. An investigation into Geli's demise was quashed shortly afterwards, and the body was sent to Vienna for burial.
Hitler subsequently wrote to the press claiming that he had not had a fight with Geli before her death, that he was not against her trip to Vienna, and that he was not against his niece becoming engaged. He added that the media were wrong and that she was not going to Vienna to get engaged in the first place.
All sorts of media headlines emerged in the days following Geli's death, including "A Mysterious Affair," "Hitler's Niece Commits Suicide," and "Hitler's Lover Commits Suicide: Bachelors and Homosexuals as Leaders of the Party." This latter article included information about another woman who had allegedly had an affair with Hitler in 1928 and subsequently attempted to take her own life.
The article commented that Geli's private life with the future Führer "took on forms which obviously the young woman was unable to bear." More notable still is the fact that the historian Robert Waite, using reports by the OSS, concluded that of the seven women who were known to have sexual relationships with Hitler, six either took their own lives or attempted to do so. This included his long-term partner Eva Braun, who attempted the act in 1932 and again in 1935.
After this, things grew quiet. Since there was no investigation and Geli's body had been sent to Vienna, there was little more to discuss. Furthermore, the Nazi Party had threatened to sue at least one paper, prompting the outlet to stop debating the story altogether.
Only one journalist continued to lead a crusade against Hitler, determined to find out the truth. Fritz Gerlich was in the middle of putting together the results of his two-year-long investigation into Geli's death when, in March 1933, members of the SA broke into his office, assaulted him, and burned all of his work. He was then imprisoned before execution in the summer of 1934.
Journalists and historians today have suggested the theory that Geli was killed because she knew too much. She was aware of her uncle's sexual interests and had already confided in several people. As such, she was eliminated to prevent her from speaking out any further.
Decades later, Geli's sister revealed that she did not believe the 23-year-old had taken her own life, and neither did her mother. This was especially so after unfinished letters were found in her room that indicated she was looking forward to the future and was hopeful about life.
Still, there are others who think she took her own life out of jealousy of Eva Braun, or all because she was pregnant, either by Hitler or by her Jewish singing teacher. It has also been proposed that prominent members of the party decided to eliminate Geli, as she was seen as a loose end who could cause them trouble.
But many people believe Hitler himself had murdered his niece after the pair had fought. Though he had an alibi at the time of the murder, his alibi came in the form of people who were under his employment. It seems reasonable to consider that those witnesses may have been forced or coerced into giving him an alibi.
Furthermore, since there was no autopsy or police examination of the crime scene, there are many things we still do not know. For example, witnesses claim that the door was locked from the inside, but as the door and lock were never examined, it is unclear if this was true.
In the months following Geli's death, Hitler is said to have fallen into a deep depression. He reportedly discussed ending his own life and was at one point almost comatose with grief.
Robert Waite wrote that with the single exception of his mother's death, no other event in his personal life had hit him so hard. A confidant also remarked that Geli's death had such a devastating effect on Hitler that it changed his relationship with other people.
Hitler failed to attend Geli's funeral and hid away in a house on the shores of the Tegernsee, a lake in southern Germany. Geli's room at the Munich apartment was left untouched as a shrine to her, and portraits of Geli were hung in Hitler's room.
But it was not just Hitler who was greatly affected by Geli's death. Her mother Angela stopped working for Hitler, and many of their family members declined to maintain any relationship with him.
Historian William Shirer claimed that Hitler declared Geli as the only woman he ever loved. To this day, however, many questions remain surrounding her death.