Two years later we meet him fighting heresy in Florence. That city, it will be remembered, was the subject of the earliest inquisitorial experiments, Frà Giovanni di Salerno, Prior of Santa Maria Novella, having been commissioned to prosecute heretics in 1228, and being succeeded after his death, in 1230, by Frà Aldobrandini Cavalcante, and about 1241 by Frà Ruggieri Calcagni. The first two of these accomplished little, being, in fact, rather preachers than inquisitors. The heretics were protected by the Ghibelline faction and the partisans of Frederic II., and heresy, far from decreasing, spread rapidly in spite of occasional burnings. When the Catharan Bishop Paternon fled, his position was successively held by three others, Torsello, Brunnetto, and Giacopo da Montefiascone. Many of the most powerful families were heretics or open defenders of heresy--the Baroni, Pulci, Cipriani, Cavalcanti, Saraceni, and Malpresa. The Baroni built a stronghold at San Gaggio, beyond the walls, which served as a refuge for the Perfected, and there were plenty of houses in the town where they could hold their conventicles in safety. The Cipriani had two palaces, one at Mugnone and the other in Florence, where troops of Cathari assembled under the leadership of a heresiarch named Marchisiano, and there were great schools at Poggibonsi, Pian di Cascia, and Ponte a Sieve.[233] The whole of central Italy, in fact, was almost as deeply infected with heresy as Lombardy, and little had as yet been done to purify it. That as late as 1235 no comprehensive attempt had been made to establish the Inquisition is shown by a papal brief addressed in that year to the Dominicans of Viterbo, empowering them, in all the dioceses of Tuscany, Viterbo, Orta, Balneoreggio, Castro, Soano, Amerino, and Narni, to absolve heretics not publicly defamed for heresy, who should spontaneously accuse themselves, provided the bishops assented and sufficient bail were given; and the bishops were ordered to co-operate. Heretics not thus voluntarily confessing were to be dealt with according to the papal statutes. At Viterbo dwelt Giovanni da Benevento, who was called the pope of the heretics, but it was not until Gregory went thither in 1237 and undertook the task of purifying the place himself that any efficient action was taken; he condemned Giovanni and many other heretics, and ordered the palaces of some of the noblest families of the city to be torn down, as having afforded refuge to heretics. At the same time the Bishop of Padua was urged to persevere in the good work, and at Parma the Knights of Jesus Christ were instituted with the same object by Jordan, the Dominican general. All this indicates the commencement of systematic operations, and the pressure grew stronger year by year. Under the energetic management of Ruggieri Calcagni the Florentine Inquisition rapidly took shape and executions became frequent, while in the confessions of the accused allusions are made to