The Salem Witch Trials were a blight on the "New World." Over 20 innocent people were put to the gallows because they had been charged and convicted of witchcraft. Looking back now we know what these were ridiculous charges, but at the time they did not have the scientific knowledge that we have now.
But before the Witch Trials in America, there was Matthew "Witch-Finder General" Hopkins, in jolly old England. Hopkins named himself the defacto "Witchfinder General" and made it his life's mission to purge England of the witches plaguing the country, all in the name of religion.
At least in Salem, the crimes purported against the people who were exectued were motivated by ignorance and fear, whereas Hopkins was fueled by greed. He was well paid for his antics across England. If we want to get literal, Hopkins can be considered Britain's first serial killer.
At the time, England was plagued by famine, disease, poverty and death, and all of this was attributed to be the work of the Devil. Hopkins, who was what we would now call a "religious fanatic", wanted to rid the world of witches and all those who would challenge God's will.
Hopkins made "witch-finding" his life's mission...