One of the most lingering images of fear and tyranny through history has to be of German dictator Adolf Hitler - a man who oversaw the killing of millions, and truly personified what it means to be evil. And while his issues with Jews were well documented, his issues with his penis weren't. Until now.

According to an exhaustive report that studied Hitler's personality, he once walked in on his parents having sex, fuelling an unhealthy obsession with his mother and hatred for his father.

The 229-page report conducted by Harvard Professor Dr Henry Murray was commissioned by the US Office of Strategic Services, a precursor to the CIA.

Source: Punemirror

Hitler apparently had a micro-penis and just a single testicle (a fact that's surprisingly well-known). 

Apart from these physical aspects, he also harboured some pretty extreme sexual fantasies.

Source: Daily Beast

Hitler apparently liked to have women defecate on him, and also enjoyed being kicked by women while having sex.

The scientific term for this poop-fetish is coprophilia.

Source: The Logical Indian

Another disturbing fact Dr Murray put forward was that Hitler had sex with his own niece. She allegedly told some people close to Hitler about it.

The news made Otto Strasser, a prominent Nazi supporter, flee the party.

Source: NY Times

So there you go, some more truly disturbing facts about Hitler, just in case all the genocide and racism wasn't enough.