It may readily be believed that these persecutions drove the Bogomiles to take refuge more and more in the Serbian regions, out of the way of the orthodox savagery of Byzantium. There were moreover reasons which diverted the current of heresy from that part of Serbia which became afterwards the nucleus of the Empire of the Némanjas. The Serbian princes who ruled over the territory now occupied by old Serbia and Montenegro were faithful sons of the orthodox church, and directed their utmost efforts to keep the shrine of St. Vladimir and the national patriarchate of Dioclea free from the contamination of Manichæism. Thus a variety of causes combined to direct the course of the new movement to the Serbian races of Western Illyricum; and in the twelfth century—the century immediately preceding the outbreak of Gnostic Puritanism in Western Europe—Bosnia had become the head-quarters of what we may now call the great Sclavonic Heresy. Thanks to the publication of many South-Sclavonic archives, we are now in a position to arrive at the tenets of the Bogomiles, from native as well as from Byzantine sources; and, as I hope to show, both the Greek and Sclavonic accounts of the sect which now plays such an important part in Bosnian history harmonize to a very great extent. The best native account that we possess of the Bogomilian heretics is to be found in the works of a Bulgarian writer, one Presbyter Cosmas, who lived at the end of the tenth century, just at the period when the heresy was striking root among the Serbs and Bosniacs, and who wrote (in his native tongue) two of his most important works against the Bogomiles—whom he considers ‘worse and more horrible than demons!’[21]