Although Stephen of Bourbon relates that a converted heretic informed him that in Milan there were no less than seventeen heterodox sects which bitterly disputed with each other, yet they can, as in France, be reduced to two main classes--Cathari, or Patarins, and Waldenses. The Cathari, it will be remembered, made their appearance in the first half of the eleventh century, at Monforte, in Lombardy, and they had continued to multiply since then. About the middle of the thirteenth century Rainerio Saccone gives us an enumeration of their churches. In Lombardy and the Marches there were about five hundred perfected Cathari of the Albanensian sect, more than fifteen hundred Concorrezenses, and about two hundred Bajolenses. The Church of Vicenza reckoned about a hundred; there were as many in Florence and Spoleto, and in addition about one hundred and fifty refugees from France in Lombardy. As he estimates the total number, from Constantinople to the Pyrenees, at four thousand, with a countless congregation of believers, it will be seen that nearly two thirds of the whole number were concentrated in northern Italy, chiefly in Lombardy, and that they constituted a notable portion of the population.[213] Lombardy, in fact, was the centre whence Catharism was propagated throughout Europe. We have seen above how for more than half a century it served as a refuge to the persecuted saints of Languedoc, and as a source whence to draw missionaries and teachers. About 1240 a certain Yvo of Narbonne was falsely accused of heresy and fled to Italy, where he was received as a martyr, and had full opportunity of penetrating into the secrets of the sectaries. In a letter to Géraud, Archbishop of Bordeaux, he describes their thorough organization throughout Italy, with ramifications extending into all the neighboring lands. From all the cities of Lombardy and Tuscany their youth were sent to Paris to perfect themselves in logic and theology, so as to be able successfully to defend their errors. Catharan merchants frequented fairs and obtained entrance into houses where they lost no opportunity of scattering the seed of false doctrine. Full of zeal and courage, the Catharan believed his faith to be the religion of the future, and his ardor courted martyrdom in the effort to spread it everywhere. Milan was the headquarters whither every year delegates were sent from the churches throughout Christendom, bringing contributions for the support of the central organization, and receiving instructions as to the symbol, changed every twelvemonth, whereby the wandering Patarin could recognize the houses of his brethren and safely claim hospitality. It was in vain that, in 1212, Innocent III. warned the heretical city of the fate of Languedoc, and threatened to send a similar crusade for its extirpation. Fortunately for the Lombards he had no one to summon to their destruction, for Germany, however desirous of conquering Italy,