Albigenses, a term popularly given to a sect of Manichaeans (q.v.), which sprang up in the south of France at the end of the twelfth century. It was from the town of Albi, where a council was held against them, that their name was derived. The principal heresies of which they were accused were a belief in dualism, the rejection of the Old Testament and the sacraments, and the doctrine that marriage and the use of ritual in Divine service were sinful. The accession of Innocent III. to the papal throne was the signal for the commencement of the persecution of the Albigenses, which continued with more or less rigour and cruelty until 1229, when a peace was concluded. This "crusade," as it was termed, was characterised by "atrocities remarkable even for a religious war," and the well-known saying of the Legate Arnold, "Slay all, God will know His own!" will serve to indicate the temper of the persecutors. Simon de Montfort, the father of the more celebrated English patriot, was the leader of the crusade, under the Pope's legates, and it was not until after the massacre of thousands of victims, and the devastation of some of the most fertile valleys of southern France, that peace was made. The Inquisition was then at liberty to work its will upon the hapless fanatics, with the result that by the middle of the thirteenth century the Albigenses had ceased to exist.