The publication of Frederick II’s Constitutions and the activities of Gregory IX introduced a new era of intolerance into Italy, where apparently tolerance had hitherto been the rule. Inquisitorial activity started in Florence and in Rome; it was carried further afield by several perfervid champions, of whom the best known was Peter Martyr, the scene of whose labours was first Milan, then Florence. In Florence persecution had become so menacing that a formidable rising was provoked. This was the occasion of Piero’s coming to Florence, where he at once formed a company on the model of one he had created in Milan for the protection of Dominicans, giving it the title of the _Compagnia della Fede_. The Florentine inquisitor, with this protection, proceeded with his persecutions and a bloody conflict was provoked, which was as much one between Guelph and Ghibelline as between orthodox and heretic. Peter Martyr led the banners of the faith with such good effect that the forces of heresy were badly beaten and the city reclaimed for Pope and Inquisition. He was next engaged as inquisitor in Cremona and again in Milan. Though there is no record of his proceedings there, that he was as ardent a persecutor as before seems proved by his assassination at Milan in 1252. As a practical memorial of the martyr’s enthusiasm a voluntary association similar to those which Piero had himself founded in Milan and Florence was formed among the upper classes of the principal Italian cities, the name _crocesegnati_ being given to them, for the protection and assistance of inquisitors. As devoted and determined a champion as even Peter Martyr had been was found in Rainerio Saccone of Vicenza, who undertook the task of combatting heresy in Lombardy, where it was very strong owing to large migrations from Languedoc. Reorganizing and strengthening the Lombard Inquisition, he achieved considerable success with the assistance of Innocent IV, who at this time issued the bull _Ad extirpanda_.[344] With the accession of Alexander IV activity in Lombardy was still further increased. The number of inquisitors was doubled, and Rainerio announced that hitherto he had shown incomparable mildness, henceforth he would be rigorous. The chief obstacle—a formidable one—to the complete success of the tribunal in Lombardy was the power of the two great Ghibelline nobles, Eccelin da Romano and Uberto da Pallavicino, into whose territories not even a determined inquisitor dared enter. A crusade against the former, organized by Alexander, after varying fortunes proved successful, and the March of Treviso, hitherto closed to the Inquisition, was laid completely open.