Oliverotto da Fermo
Oliverotto Eufferducci, better known as Oliverotto da Fermo, was born in Fermo around 1475. In 1495 he associated with Paolo Vitelli and fought with him first at Pisa and then in Naples for the French. A few years later Oliverotto and Paolo were fighting against the Venetians. In 1499 the two were fighting for the Florentines against Pisa, but both were accused of treason by Florence. Paolo was summarily put to death while Oliverotto was spared due to the intervention of the government of Fermo. He then united with Vitellozzo Vitelli, Paolo's brother, and both went into the service of Cesare Borgia, at this time better known as Duke Valentino. After the conquest of Piombino for the Duke, Oliverotto returned to Fermo with the aim of becoming lord of that city—a position held at that time by his maternal uncle Giovanni Fogliani. So Oliverotto devised a stratagem, as described by Machiavelli:

He [Oliverotto] wrote to Giovanni Fogliani that, having been away from home for many years, he wished to visit him and his city, and in some measure to look into his patrimony; and although he had not laboured to acquire anything except honour, yet, in order that the citizens should see he had not spent his time in vain, he desired to come honourably, so would be accompanied by one hundred horsemen, his friends and retainers; and he entreated Giovanni to arrange that he should be received honourably by the citizens of Fermo, all of which would be not only to his honour, but also to that of Giovanni himself, who had brought him up. Giovanni, therefore, did not fail in any attentions due to his nephew, and he caused him to be honourably received by the Fermans, and he lodged him in his own house, where, having passed some days, and having arranged what was necessary for his wicked designs, Oliverotto gave a solemn banquet to which he invited Giovanni Fogliani and the chiefs of Fermo. When the viands and all the other entertainments that are usual in such banquets were finished, Oliverotto artfully began certain grave discourses, speaking of the greatness of Pope Alexander and his son Cesare, and of their enterprises, to which discourse Giovanni and others answered; but he rose at once, saying that such matters ought to be discussed in a more private place, and he betook himself to a chamber, whither Giovanni and the rest of the citizens went in after him. No sooner were they seated than soldiers issued from secret places and slaughtered Giovanni and the rest. After these murders Oliverotto, mounted on horseback, rode up and down the town and besieged the chief magistrate in the palace, so that in fear the people were forced to obey him, and to form a government, of which he made himself the prince. He killed all the malcontents who were able to injure him, and strengthened himself with new civil and military ordinances, in such a way that, in the year during which he held the principality, not only was he secure in the city of Fermo, but he had become formidable to all his neighbours (N. Machiavelli, The Prince, chapter 8 - translated by W. K. Marriott).

In May 1502 Oliverotto conquered Camerino for Cesare Borgia, but realizing that the Duke was becoming stronger and stronger, he attended the meeting at La Magione, with the Orsinis, the Baglionis, Petrucci, Bentivoglio, Vitelli and others, on October 9. Although Oliverotto was against Paolo Orsini's line of reconciliation with Cesare Borgia, nonetheless he took Sinigallia in Cesare's name. But this didn't change Borgia's secret design and had him arrested and strangled, together with Vitellozzo Vitelli, on December 31, 1502.