Hitler's Niece by Ron Hansen

Adolf Hitler is a nobody who can't draw, can't do well in a school atmosphere and has a genuine hatred for the Jewish people. He comes to his half-sisters apartment to maybe get something to eat and is introduced to his young niece, Angelica (Geli, pronounced gaily) Raubal.

Hitler is in his take Germany-by-storm phase, and is doing well, and requests his sister and niece to live with him as his caretakers. 

He falls in love with his beautiful niece, although she is probably not feeling the same way about him. She eventually comes to love him, even in his weirdness. The relationship is strange and not always very kosher.

Although this is written as a novel, I am sure that most of the history in this book is factual. Unfortunately, the one part of the book that you would love to know the truth about will never be known for a fact, as it is of a personal nature and the persons are deceased. I walked away from reading this book with a strong, fresh hatred for Adolf Hitler, not that I liked him to begin with.
Ron Hansen definitely did a lot of research on a woman who doesn't have too much history written about her and filled in gaps with aplomb.