[56] persecution, but it was not systematic. There is reason to think that in the pursuit of heresy the Church was mainly guided by considerations of its temporal interest, and was roused to severe action only when the spread of false doctrine threatened to reduce its revenues or seemed a menace to society. At the end of the twelfth century Innocent III became Pope and under him the Church of Western Europe reached the height of its power. He and his immediate successors are responsible for imagining and beginning an organized movement to sweep heretics out of Christendom. Languedoc in Southwestern France was largely populated by heretics, whose opinions were considered particularly offensive, known as the Albigeois. They were the subjects of the Count of Toulouse, and were an industrious and respectable people. But the Church got far too little money out of this anti- clerical population, and Innocent called upon the Count to extirpate heresy from his dominion. As he would not obey, the Pope announced a Crusade against the Albigeois, and offered to all who would bear a hand the usual rewards granted to Crusaders, including absolution from all their sins. A series of sanguinary wars followed in which the Englishman, Simon de Montfort, took part. There were [57] wholesale burnings and hangings of men, women and children. The resistance of the people was broken down, though the heresy was not eradicated, and the struggle ended in 1229 with the complete humiliation of the Count of Toulouse. The important point of the episode is this: the Church introduced into the public law of Europe the new principle that a sovran held his crown on the condition that he should extirpate heresy. If he hesitated to persecute at the command of the Pope, he must be coerced; his lands were forfeited; and his dominions were thrown open to be seized by any one whom the Church could induce to attack him. The Popes thus established a theocratic system in which all other interests were to be subordinated to the grand duty of maintaining the purity of the Faith. But in order to root out heresy it was necessary to discover it in its most secret retreats. The Albigeois had been crushed, but the poison of their doctrine was not yet destroyed. The organized system of searching out heretics known as the Inquisition was founded by Pope Gregory IX about A.D. 1233, and fully established by a Bull of Innocent IV (A.D. 1252) which regulated the machinery of persecution “as an integral part of the social edifice in every city and every [58] State.” This powerful engine for the suppression of the freedom of men’s religious opinions is unique in history.