Over 2 centuries nearly 60.000 people, mostly women where put to death for crimes of witchcraft, in a series of hunts and trials that spread across Europe and the Americas. Those found guilty where hanged, beheaded or burned.
Heinrich Kramer, a Dominican monk, was looking for witches. His fight against the witches begins as a one man crusade. He went to Rome to get an official writ from the Pope that declared Kramer to be responsible for eradicating witches and got one. But the first witch trial he set up in Austria didn't go as wanted, Kramer was frowned and laughed upon and had to leave the city with the tail between his legs.
He didn't stop there though. Kramer was obsessed with the idea that woman were weak, in every aspect, their bodies, mind and souls. He found an outlet for his opinion and started writing the Malleus Maleficarum, literaly translated to 'the hammer of the female evil do-ers'. In his book he wrote how you could recognize witches and how to torture them for a confession. The book became immensely popular and was used by witch hunters for decades.
I include a page that discusses whether witches can actually harm or transform people. Kramer concludes that witches could indeed transform, but that it was merely an illusion. If someone were transformed into an animal, it was not a genuine physical transformation. He also states that demons can indeed cause harm, but only to the extent permitted by God.