Arnaud Amaury ( ; died 1225 ) was a Roman Catholic Cistercian abbot who played a prominent role in the Albigensian Crusade . Prior to the massacre of Béziers , it was reported that Amalric , when asked how to distinguish Cathars from Catholics , responded , " Kill them all ! God will know his own . " Whether this was actually said is sometimes considered doubtful , but , according to historian Joseph Strayer , it captures the " spirit " of the Crusaders , who killed nearly every man , woman , and child in the town
massacre of Béziers
Massacre at Béziers
Arnaud Amalric