1209–1229Reputable sourceWell documented
The Albigensian Crusade
On the timeline · around 1209–1229 ·
What happened
The papacy launched a crusade not against Muslims but against fellow Christians: the Cathars, a heretical sect in southern France. The Albigensian Crusade devastated the region — the sack of Béziers alone killed thousands — and paved the way for the medieval Inquisition to hunt down remaining heretics.
Why it matters
The Albigensian Crusade showed the crusading ideal turned inward, against dissent within Christendom itself. It crushed a flourishing culture, extended the French crown's power southward, and helped give birth to the Inquisition.
Sources
- World History Encyclopedia. Albigensian Crusade · Reputable source