Field of the burned

The Cathars, from the Greek 'pure ones,' were a dualistic Christian movement active in northern Italy and southern France. They believed in two gods: a good god and a bad god. They held that the soul is trapped in the earthly realm of the evil god and needed to reincarnate until achieving salvation to reach the good god.

The Catholic Church denounced them as heretics. Pope Innocent III sought to eradicate Catharism by sending missionaries and pressuring local authorities to act against them. His 20-year campaign weakened the movement, but the Medieval Inquisition finished the job. The last stronghold was Castle Montségur.

Over two hundred Cathars who refused to renounce their faith walked down from the fortress into a massive pyre, choosing fire over recanting. Within a century, Catharism had been almost entirely erased.

Those who recanted were forced to sew yellow crosses onto their clothing and live apart from other Catholics. Which reminds me of what Hitler's regime did to the Jews—they were also forced to sew a yellow Star of David onto their clothing.

After looking it up, it turns out the architect behind sewing symbols onto people of different religions was indeed Pope Innocent III. He didn't just target Cathars, but also Jews and Muslims, requiring them all to wear symbols that distinguished them from Christians.