Upon his return to Florence in 1574, he found himself facing altered political dynamics. Cosimo I's death had deprived him of his main support. The new Grand Duke, Francesco, distrusted him and sought to prevent him from establishing a close relationship with his influential brother,
Cardinal Ferdinando. Allegedly, he blamed Orsini for protecting an individual accused of killing one of his servants. Subsequently, he accused Orsini of murder and, on February 15, 1576, sentenced him in absentia, confiscating his assets. Orsini had already sought refuge in France, where he was appointed gentleman of the chamber by Henry III. Nevertheless, the reasons behind this reversal of fortune remain somewhat obscure, as do the true motives behind his journey to Paris. After departing Florence, he maintained a correspondence with
Bartolomeo Concini, Francesco's secretary, Ferdinando de' Medici, and the Grand Duke himself. On November 30, 1577, in Paris, he fell victim to an arquebus attack and succumbed to his injuries two days after. The primary culprit behind the murder was Ambrogio Tremazzi, accompanied by an individual named Ieronimo Savorano. In a letter addressed to
Antonio Serguidi, secretary of Grand Duke Francesco, Tremazzi confessed to receiving the assignment to assassinate Orsini from Count Ridolfo Isolani and Don
Pietro de' Medici, the youngest son of Cosimo I. Tremazzi painstakingly reconstructed the steps taken to approach Troilo, whose access proved challenging due to Troilo's role as a gentleman of the chamber to Henry III, spending significant time at the royal court. According to the contemporary account of the nuncio in Paris,
Antonio Maria Salviati, Orsini was aware of his assailant's identity but chose not to reveal it, even on his deathbed, and forgave the individual. The news of the murder garnered considerable attention in the reports of ambassadors and notices. The name of a Caracciolo, of Neapolitan origins and a member of the Order of the
Knights of St. Stephen, was also mentioned as a possible perpetrator. However, widespread suspicion circulated regarding the involvement of Sinolfo Saracini, the grand ducal ambassador in France, and the ducal secretary
Curzio Picchena, who were not strangers to orchestrating ambushes against Florentine exiles. A Florentine exile named Bernardo Girolami accused them to the King, leading to a search of the ambassador's residence, but the investigations yielded no results. The historical reconstructions of the subsequent period are connected to the different readings of the story: Orsini's diplomatic missions (particularly those in France) are explained by some with Cosimo I's desire to distance Orsini from his daughter; by others with political purposes and diplomatic representation. By some, the killing was seen as extreme revenge by Grand Duke Francesco after the death of his sister Isabella, killed at the behest of her husband Paolo Giordano who had discovered her betrayal with Orsini or, instead, with political reasons, linked either to the campaign to eliminate the Florentine exiles in France (Galluzzi, 1781; Diaz, 1987), or to the ambiguity of the position that Orsini had assumed in France, due to which he would have lost the trust of the Grand Duke Several years later, Queen Catherine de' Medici expressed her dissatisfaction with Orsini's murder to Andrea Albertani, dispatched from Florence to recover a substantial credit. During a period of political tension with Tuscany, Queen Catherine disapproved of the systematic elimination of Florentine exiles in France, as it jeopardised the king's sovereignty. == Personal life ==