thank you for mentioning the cathars. along with the templars, history tells us very little about the them. they dared to oppose the kings of france and the church hierarchy. southern france whispers secrets from aigues morte where the ships of the crusade set out for the holy land to albi and narbonne which were cathar strongholds.
My daughter gave me "The Perfect Heresy", by Stephen O'Shea, a beautifully written book on the slaughter of these heretical Christians by the Crusaders. How a corrupt Pope, afraid of their power, forced a war against this saintly group and those that protected them, that led to the genocide of 20,000 men, women and children and the burning of the city of Bezier.
And gave us that infamous quote by the Crusader's leader, "Kill them all, God will know his own".
Absolutely fascinating medieval history.