The Cathars — from the Greek katharos, meaning "pure" — were a Christian religious movement that flourished in southern France (the region known as the Languedoc) and parts of northern Italy during the 12th and 13th centuries. They called themselves simply Good Christians or Good Men and Women. The name "Cathar" was applied to them by their opponents.
They were not a fringe movement. By the late 12th century, Catharism had become the dominant religion in much of the Languedoc — with the tacit support of the local nobility, including the powerful Counts of Toulouse. Major cities like Albi, Carcassonne and Béziers had large Cathar communities. The movement had its own clergy (the perfecti — the perfected ones), its own sacrament (the consolamentum), its own ecclesiastical organisation and its own theology that represented a direct and total challenge to Catholic Christianity.
The Cathars were connected to similar dualist movements across Europe — the Bogomils of Bulgaria and the Balkans appear to have been an earlier related tradition, and there were connections to dualist communities in northern Italy. Whether these movements shared a common origin or developed independently is debated. What is clear is that Catharism was not a local aberration but part of a broader current of dualist Christianity that flowed through medieval Europe.
Socially, the Cathars were remarkably egalitarian for their time. Women could become perfecti — full clergy — which was unthinkable in the Catholic Church. The perfecti lived in genuine poverty, refusing to own property, eat meat or engage in sexual relations. They were respected even by many Catholics for the integrity of their lives. The contrast with the wealth, corruption and moral laxity of the contemporary Catholic clergy was not lost on the population of the Languedoc.