Eva Braun was Hitler's mistress throughout the final twelve years of his life, and on the day before his death, he married her. Eva spent much of her life with Hitler far from Berlin, waiting for her sweetie to call for her, and attempting suicide several times out of frustration.
With his characteristic tact, Shirer describes Braun as being "interesting for her role in the last chapter of this narrative but not interesting in herself," and he adds that she "was not a Pompadour or a Lola Montez" (6.31.33). That is, not a very glam mistress. (We're being sarcastic about the "tact," by the way.)
Shirer goes on to characterize Braun by noting that "Hitler, although he was undoubtedly extremely fond of her and found relaxation in her unobtrusive company, had always kept her out of sight, refusing to allow her to come to his various headquarters, where he spent almost all of his time during the war years, and rarely permitting her even to come to Berlin." (6.31.33)
She "had a birdlike mind and made no intellectual impression on Hitler at all," he continues later, speculating further that "perhaps this is one reason he preferred her company to that of intelligent women" (6.31.38).
Like her husband, Eva Braun died in the mid-afternoon on April 30, 1945. Whereas Hitler committed suicide by shooting himself, Braun used poison. Still, we don't think she had much choice in the matter.
Alois Hitler (née Schicklgruber) was Adolf Hitler's father. Having died when Adolf was just thirteen years old, he doesn't get a lot of attention in The Rise and Fall of the Third Reich. Even so, Shirer spends some time discussing the role he played in young Adolf Hitler's life.
Drawing on Hitler's own descriptions of his father in Mein Kampf, Shirer writes of a "bitter, unrelenting struggle" between the young man and his "hardened and […] domineering father" (1.1.40). Alois Hitler wanted his son to train for civil service, but young Adolf wanted to be an artist instead.
From Shirer's point of view, young Adolf's relationship with his father may not have been the most formative influence on his later life, but it did "arouse the first manifestations of that fierce, unbending will which would later carry him so far despite seemingly insuperable obstacles and handicaps" (1.1.40).
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Klara Poelzl was Adolf Hitler's mother. She was forty-two years old when her husband Alois Hitler died, and from that point on she struggled to support young Adolf and his sister Paula "on the meager savings and pension left her" (1.1.64). She supported Adolf for several years while he was a high-school dropout, and there's no evidence he tried to help her out by getting a job. He did return to Linz from Vienna to help take care of her during her terminal fight with breast cancer. She died in 1908, when Adolf was nineteen.
Geli Raubal was Hitler's niece—the daughter of his half-sister, Angela Raubal. She was also, in Shirer's words, the woman with whom Hitler had "the only truly deep love affair of his life" (1.1.33).
We guess that means "tough luck," Eva Braun.
Shirer describes Raubal as having "flowing blond hair, handsome features, a pleasant voice and a sunny disposition which made her attractive to men" (2.5.76). She was twenty years old when she and Hitler met in 1928, and just twenty-three years old when she died.
On September 18, 1931, while staying with Hitler in Munich, Raubal "was found shot dead in her room" (2.5.81). Her death was found to be a suicide, and although Shirer makes note of the "murky gossip" which suggested that Hitler himself had had her killed, he argues that "no credible evidence ever turned up to substantiate such rumors," and that Hitler was genuinely "struck down by grief" and "inconsolable" for months (2.5.81-83).