Pope Innocent III 

Pope Innocent III ruled the Catholic Church from 1198 until 1216.

A real poor name for such a low-life person.

He was the Pope who ordered a Crusade against the Cathars that became known as the Albigensian Crusade.

Pope Innocent III seems to have ordered the murder of these Christians because they would not accept the total authority of the Pope and the Catholic Church.  Of course he was just doing as most religions do and was eliminating the competition by whatever means he could so do.

Most of these Christians were wiped out by the  early 14th century.