This document provides an overview of several medieval heresies including the Catharists, Waldensians, Bogomils, Fraticelli, Patarine, and Apostolici. It defines heresy and includes perspectives on heresy from historical figures. For each heresy, it summarizes their beliefs, origins, and how they were viewed by the Catholic Church and faced persecution. It also notes how heretics were sometimes identified through their dress, phrases, or ideas that differed from Church doctrine.