From Thrace, meanwhile, their propaganda spread into Bulgaria, where it prospered, with the help of refugees from Armenia. In the tenth century they were to some extent favoured as a useful bulwark against the Slavs; but in the eleventh they were again persecuted; and as the malcontents of the empire in general tended to join them they became the ruling party in Bulgaria. Thus it came about that the name Bulgar, Bulgarian, became a specific name in mid-Europe for heretic (and worse), surviving to this day in that sense in the French form of bougre. The Paulicians, further, had their own extremists, who held by the old Marcionite veto on marriage, and received the Greek name of cathari, “the pure”—a title sometimes given to the whole mass, from whom, however, the purists were in that case distinguished as perfecti. Either from the Cathari or from the Chazari, a Turkish tribe whose Christianity in the ninth century was much mixed with Mohammedanism, came the Italian nickname gazzari, and the German word for heretic, ketzer. Yet another eastern sect, the Slavonic Bogomilians, who remained monotheistic as against the dualism of the Paulicians, joined in the wave of new beliefs which began to beat from the East on central Europe.

From the very beginning of the eleventh century, outbreaks of the new heresy, always anti-clerical and anti-ceremonial, occurred at intervals in France, northern Italy, and Germany. In some cases, the opposition to priests, images, and Virgin-worship extended to a denial of all miracles and sacraments, and an assertion of the eternity of matter—apparent signs of Saracen philosophic influence. But the movement developed a thoroughness of enmity to everything ecclesiastical, that told of a quite independent basis in the now widespread hostility to the Church of Rome outside of its centre of wealth and power. For one or two generations the crusades drew off the superfluous energy of Europe, and the new heresies were somewhat overshadowed; but in the first half of the twelfth century, when the crusades had lost all religious savour, anti-clericalism sprang up on all sides. Tanquelin in Flanders; Peter de Brueys (founder of the Petrobrussians) in Languedoc; the monk Henry in Switzerland and France; Eudo of Stello in Brittany, and Arnold of Brescia in Italy, all wrought either religiously or politically against the Church; and all died by her violence, or in prison. Arnold, the most capable of all, was a pupil of Abailard, and his doctrine was that the entire vested wealth of the Church should be taken over by the civil power, leaving the clergy to live sparingly by the gifts of the faithful. His movement, which lasted twenty years, and was very strong in Lombardy, went so far as to set up a short-lived republic in Rome; but it needed only a combination of the pope and the emperor, Frederick Barbarossa, to bring the republic to the ground, and Arnold to crucifixion.

Among the other revolters there was a good deal of fanaticism; but all were more or less emphatic in denouncing priestly pretensions, sacraments, cross-worship, prayers for the dead, penance, image-worship, church bells, altars, and even churches. It seemed as if the end of the Church had begun. For, though each new prophet in turn was slain, new heretics seemed to rise from the ashes. With various positive tenets, they were at one in their enmity to the priesthood. In Italy there flourished a sect called the Pasagini (apparently = Passagieri, Crusaders) or the Circumcised, who returned to the law of Moses and to Ebionite views of Jesus; in France, a different order of zealots, called Caputiati from the habit of carrying an image of the Virgin on their hats, stood for a return to primeval equality and liberty. Between such types of heresy stood the Apostolici, mostly poor working-folk, but with powerful sympathizers, who urged a return to the “apostolic” ideal of poverty and simplicity, and further discouraged marriage, calling themselves “the chaste brethren and sisters.” Two of their leaders, Sagarelli and Fra Dolcino, had shown the usual aversion to the Church, Dolcino predicting the formation of native States and the purification of the papacy; so they, too, were put to death, being burnt at the stake. And still new revolters appeared.

At this stage there came to the front the sectaries known in history as the Vaudois or Waldenses, a name standing properly for the inhabitants of the Vaux or Valleys of Piedmont, but further connected with the teaching of one Peter Waldus, a Lyons merchant, whose followers received also the name of the Poor Men of Lyons. How far the anti-Catholic tenets of the Waldenses derive from ancient heresy is uncertain; but it is clear that late in the twelfth century they were acted on by the immense ferment of new ideas around them. Like the Paulicians, they insisted that the laity should read the Bible for themselves; and their men and women members went about preaching wherever they could get a hearing, and administering the eucharist without priestly sanction. At the same time they condemned tithes, opposed fasting and prayers for the dead, preached peace and non-resistance, denied the authority of the pope, and impeached the lives of the clergy.

All of these forces of heresy, and yet others, were specially at work in the rich and prosperous region of Languedoc, the patrimony of Count Raymond of Toulouse. Paulicians and Waldenses, Cathari, Albanensians or sectaries of Albano, Albigensians or sectaries of the town of Alby or the district of Albigensium, Bogomilians, Apostolici, Caputiati, and nondescript Paterini (a Milanese name for a popular faction)—all were active in the name of religion; and in addition there were at work heretics of another stamp—the gay, wandering Goliards or satirical poets and minstrels, who loved the priests and the papacy as little as did the zealots; and the graver doubters who had got new views of life from Saracen science and philosophy. As against the whole amorphous mass of misbelief, the papacy planned and effected a stupendous crusade of slaughter.

From the first the Manichæans, as the Church loved to call the heretics indiscriminately, had been bloodily punished. One bishop of the eleventh century, Wazon of Liège, is to be remembered as having protested against the universal policy of slaughter; and another, Gerhard of Cambrai and Arras, is said to have won over some heretics by persuasion; but these were voices in the wilderness. Fire, sword, halter, and cross were the normal methods of repression; and during the eleventh and twelfth centuries thousands probably so perished. But the campaign which came to be known as the Albigensian crusade was planned by Pope Innocent III to outdo all the isolated punishments of the past, and it succeeded. Grounds for quarrel with the Count of Toulouse were easily found; and the offer of indulgences, on the lines laid down in the crusades against the Saracens, brought eager volunteers from all parts of Europe, for only forty days’ service was now called for. The submission of Count Raymond was not permitted to check the massacre of his subjects. It was in the first campaign that the papal legate Arnold, abbot of Cliteaux, when asked at the storming of Beziers how the heretics were to be distinguished from the true believers, gave the historic answer, “Kill all; God will know his own.” By his own account they killed in that one place fifteen thousand men, women, and children. The chroniclers, who make the slain twice or thrice as many, tell how seven thousand of them were found in the great church of Mary the Magdalene—her from whom, in the legend, had been cast out seven devils without letting of blood.

Begun in 1209, the Albigensian crusades outlasted the life of Innocent III, who grew sick of the slaughter while the priesthood were calling for its extension. They praised in particular the Anglo-French Simon de Montfort, who slew many of his victims by torture, and tore out the eyes of many more. For nearly twenty years the wars lasted, plunder being a sufficient motive after heresy had been drowned in blood or driven broadcast throughout Europe. It has been reckoned that a full million of all ages and both sexes were slain. Yet as late as 1231 Pope Gregory IX was burning troops of the heretics at Rome, and causing many more to be burned in France and Germany.

The precocious civilization of Languedoc and Provence was destroyed, and the region became a stronghold of Catholic fanaticism; but the political diversity of Europe baffled the papal hope of destroying heresy. Thenceforth the anti-clerical animus never died out: in the course of the thirteenth century it reached even England, then the most docile section of the Catholic fold. Generations before Wiclif, there were heretics in the province of Canterbury who denied the authority of the pope and even of the Fathers, professing to stand solely on the Bible and the principle of “necessary reason.” Wiclif stood on a less heterodox plane, impugning chiefly the extreme form of transubstantiation and the practices of the begging friars; and he was proportionately influential. In the fourteenth century, when international crusades of repression had become politically impossible, the critical spirit is seen freshly at work on anti-papal lines in England, Flanders, France, Germany, and Bohemia, as well as in Italy; and again, the more energetic began in their earnest ignorance to frame new schemes of life in the light of their sacred books. The lapse of time and the continuance of orthodox culture had made an end of the old Paulician heresy as such; and of the new movements many, like that set up by Saint Francis in the period of the Albigensian crusades, were meant to be strictly obedient to the Church. Such were the “Brethren of the Common Lot,” a body set up in Holland by educated Churchmen after the so-called Beghards (otherwise Beguins or Beguttæ) had there for a time flourished and degenerated. But the Beghards and the “Brethren of the Free Spirit,” who spread widely over northern Europe, had not only aimed at a communal life, but developed the old tendency to pantheism, now gaining ground philosophically on the lines of Averroism. Even among the Franciscans the “Spirituals,” who resented the falling away of the order from its ideals of poverty, became heretical. Some adopted the new “Eternal Gospel,” by Abbot Joachim of Flora in Calabria, in which it was declared that there now began a new dispensation of the Holy Spirit, superseding that of Jesus. Others, called the Fraticelli, or Little Brothers, had a “Gospel of the Holy Spirit,” composed by John of Parma. In both cases the spirit of revolt against the Church was marked.

Of the heresy of the fourteenth century the high-water mark is seen in English Lollardism, which, without touching on the philosophical problem, proceeded on the basis of the teaching of Wiclif to a kind of religious rationalism which not only repudiated the rule of the pope but rejected the institutions of religious celibacy, exorcisms, priestly benedictions, confession and absolution, pilgrimages, masses for the dead, and prayers and offerings to images; and even carried the ethical spirit to the point of denouncing war and capital punishment. In that age, such an ethic could not long thrive. Lollardism, encouraged by the self-seeking nobility while it menaced only the wealth of the Church, which they hoped to gain, was trodden down by them in conjunction with the king and the Church when it turned against the abuses of feudal government. But its destruction was most effectually wrought through the national demoralization set up by the new imperialism of Henry V, who, after passing a new statute for the burning of heretics, won the enthusiastic loyalty of his people by his successful invasion of France. In the corruption of that policy of plunder, and in the ensuing pandemonium of the Wars of the Roses, Lollardism disappeared like every other moral ideal. The time for a union of critical and rapacious forces against the hierarchy was not yet; and when it came in the sixteenth century the critical spirit was on the whole less rational than it had been at the beginning of the fifteenth.