The Cathars, who never described themselves using that word (they called themselves chrétiens or bonshommes), served the so-called pure faith. In this they opposed the Church, which in their view had forgotten the lesson of the Holy Scriptures to devote itself to the struggle for power and money.
It was in Occitania, the area occupied today by the regions of Languedoc-Roussillon and Midi-Pyrénées, that the teachings of the Cathars took the firmest hold. The towns of Toulouse, Albi (incidentally, this period became known as the Albigensian crusade), Foix, Mirepoix and Carcassonne served as their allied bases.
For a long time the Catholic Church took a conciliatory tone, attempting to halt the spreading influence of the Cathars, supported by the counts of Toulouse and their vassals.
Things came to a head when a Papal legate was murdered. In 1209 Pope Innocent III ordered a vast offensive that quickly took on a political dimension. As a reward for their efforts, the crusaders were entitled to take possession of the property and land owned by the supporters of Catharism. As a result, the French crown was gradually able to annex Occitania, which at the time was independent.
For 20 years, the crusade that began at Béziers (where 20,000 were killed) laid waste to the South of France. Simon de Montfort, baron of the province of Ile de France, led the crusade. However, despite a series of conquests, Catharism held out.
In 1226 a second crusade was launched on the authority of Louis VIII. The Inquisition came to Toulouse and elsewhere in the region and a time of interrogations and executions began, with heretics burned at the stake. The seat of the Cathar church, Montségur fell in 1244 and in 1271 the county of Toulouse became part of the kingdom of France.
But it was not until 1321 that the last known Cathar, Guillaume Bélibaste, was burned at the stake in Villerouge-Termenes (Aude). So it was that the crushing of the Cathar religion took more than a century.