What did the heretics preach? How did the Catholic Church fight heretics?

As a rule, heretics preached Christian teachings either with deviations from the generally accepted doctrine, or such a teaching that was completely contrary to the official church. Because of such heretical teachings, many wars broke out in Medieval Europe.

The Catholic Church fought the heretics in every possible way. So-called inquisitors with almost unlimited powers were appointed, armed detachments and entire armies were assembled to fight against heretics. An example of this is the Albigensian Crusade.

The heretics caught alive were subjected to all sorts of sophisticated tortures in order for them to confess that they had deceived people. Often, the torture and execution of heretics were paraded to the common people.