Ailurophobia is known as the fear of cats and feline creatures.  People suffering from this silly condition are outright terrified of these fuzzy creatures, and in history there is only one extreme case of Ailurophobia that ended in absolute disaster.  This would be the peculiar story of Pope Gregory IX.

In the 1220's, A holy document titled 'Vox in Rama' was published by Gregory.  This document spoke against a German heresy called Luficerian, a form of devil worship, but also had another little added bonus.  The document detailed that cats, specifically black, where incarnation of Satan.  To make matters worse, This document also served as a condemning death warrant to kill the felines as devils.  Thousands of cats were exterminated because a church written text, thus leading to an unexpected side-effect.

Many people know of the Bubonic plague, a disease which caused more than 100 million deaths, and it is common knowledge of how it spread.  The disease was found mainly on fleas that lived on rats...see the picture.  Yes, the foolish extermination of our furry friends actually allowed the rat population to increase due to lack of predators.  While the Pope's decision to kill cats wasn't solely to blame for Black Death, it did serve as a motivating factor.  Guess this means that cats weren't demons after all...?