To recount the full history of the castle needs a book to itself, and would include not only the history of Assisi but almost of all Umbria.[111] The possession of the Rocco Maggiore entailed that of the Rocca Minore and gave undisputed sway over Assisi, so that the desperate efforts made to hold it can be understood. During the intervals when Papal authority was relaxed, we find the names of many famous people whose armies fought for this much contested prize. Biordo Michelotti, Count Guido of Montefeltro, the two Piccininos, Francesco Sforza and Gian Galeazzo Visconti, were in succession its owners. Cosmo de' Medici obtained it from Pope Eugenius IV, in payment of a bad debt, and a Florentine governor ruled over it for a year. It even, together with the town of Assisi, became the property of Lucrezia Borgia, who received it from Alexander VI, as part of her dower on her marriage with Giovanni Sforza, Lord of Pesaro. Sometimes it happened that a private citizen of Perugia conceived the ambitious scheme of making himself master of the castle, and by fraud the Castellano would be enticed outside the gates and murdered with his family. But it always ended by Perugia, fearing the wrath of the Pope, or not liking one of their own citizens to gain so much power, sending an army to dislodge the tyrant, who soon lost his head. Sometimes criminals were kept imprisoned in the castle; we can still see the room in the keep where they scratched their names upon the wall, with many references to their horror of the place, and a roughly traced heart pierced with an arrow. Ordinary malefactors were shut up in a dark cell on the stairs. When their crimes merited death they were executed on the Piazza della Minerva, or if time pressed, the Castellano hanged them from the battlements of the fortress or threw them out of a window into the ravine below. The governors had a difficult and not a very peaceful time, for they had not only to guard against outside foes, but occasionally against a faction who attempted to get possession of the castle, and great on those occasions was the fight outside its walls. It was in vain that they took every precaution for the general safety, that a night guard walked up and down the Assisan streets playing his castanets to warn off all evil-doers, or that men-at-arms watched incessantly from the castle battlements. In the sixteenth century the castle became a prey to the rival families of the Nepis and the Fiumi who divided Assisi between them. First it fell into the hands of Jacopo Fiumi and the Pope, Alexander VI, furious when he heard of this citizen's audacious act, wrote that "by love or by force" he would have his fortress back again; but Jacopo remained impervious to threats or promises and held out for another year, until the Priors fearing the anger of the Pope came to an agreement with him. Some thirty years later the Nepis obtained possession of it by treachery and violence, and it required