The Crusaders captured the small village of Servian and then headed for Béziers , arriving on July 21 , 1209 . Under the command of the papal legate , Arnaud Amalric , they started to besiege the city , calling on the Catholics within to come out , and demanding that the Cathars surrender . Neither group did as commanded . The city fell the following day when an abortive sortie was pursued back through the open gates . The entire population was slaughtered and the city burned to the ground . It was reported that Amalric , when asked how to distinguish Cathars from Catholics , responded , " Kill them all ! God will know his own . " Historian Joseph Strayer doubts that Amalric actually said this , but maintains that the statement captures the " spirit " of the Crusaders , who killed nearly every man , woman , and child in the town
slaughtered
Massacre at Béziers
Albigensian Crusade