The Cathars and Albigensian Crusade: When the Catholic Church Massacred 20,000 in a Single Day In medieval southern France, a Christian sect called the Cathars believed the physical world was evil, created by Satan, and the only path to salvation was rejecting all earthly pleasures. Their most devoted followers, the "perfecti," lived in extreme poverty, refused to eat meat or have sex, and practiced a death ritual called the "Endura" - voluntarily starving themselves to escape their evil bodies faster. By 1200, they had converted much of southern France, and the Pope was terrified. In 1209, Pope Innocent III launched the Albigensian Crusade - a 20-year holy war to exterminate the Cathars. The first target was the town of Béziers. When the crusader army arrived, they asked the papal legate how to distinguish Catholic residents from Cathar heretics. His alleged response became one of history's most chilling quotes: "Kill them all. God will know his own." In a single day, crusaders slaughtered approximately 20,000 men, women, and children - Catholic and Cathar alike - and burned the city to ashes. The crusade became a bloodbath that lasted two decades. At Carcassonne, thousands were expelled and left to die. At Toulouse, Simon de Montfort led brutal sieges. The final stand came at Montségur fortress in 1244, where 200+ Cathar perfecti were besieged for months. When the fortress finally fell, the perfecti were given a choice: renounce their faith or burn. All 200+ chose the flames and were burned alive in a massive pyre at the base of the mountain. But the crusade didn't end with Montségur. The Catholic Church established the Medieval Inquisition specifically to root out remaining Cathars, torturing suspects and burning survivors at the stake for decades. Southern France was devastated, its distinct culture crushed, and the entire region absorbed into the French kingdom. The Cathars were wiped from existence - but legends persist of a great Cathar treasure hidden before Montségur fell, never found to this day. This episode explores Cathar beliefs and the Endura starvation ritual, the massacre at Béziers and "kill them all," the 20-year war of extermination, the mass burning at Montségur, the birth of the Inquisition, and the mystery of the lost Cathar treasure. Keywords: weird history, Cathars, Albigensian Crusade, medieval heresy, Inquisition, Crusades, medieval France, religious persecution, Montségur, medieval warfare, Pope Innocent III, religious extremism, siege warfare Perfect for listeners who love: medieval history, Crusades, religious persecution, siege warfare, religious extremism, lost treasures, and holy wars that shaped Europe. Warning: This episode contains descriptions of mass murder, religious violence, and execution by burning. Listener discretion advised.