Here in Assisi, too, he received the Siennese envoys who came to wait upon him, and he demanded that, out of respect for the King of France, they should drive out Pandolfo Petrucci from Siena. For, to use his own words, " having deprived his enemies of their weapons, he would now deprive them of their brain," by which he paid Petrucci the compliment of accounting him the " brain " of all that had been attempted against him. To show the Siennese how much he was in earnest, he leaves all baggage and stores at Assisi, and, unhampered, makes one of his sudden swoops towards Siena, pausing on January 13 at Castel della Pieve to publish, at last, his treaty with Bentivogli. The latter being now sincere, no doubt out of fear of the consequences of further insincerity, at once sends Cesare 30 lances and 100 arbalisters under the command of Antonio della Volta.
It was there in Assisi, on the morning of striking his camp again, that Cesare completed the work that had been begun at Sinigaglia by having Paolo Orsini and the Duke of Gravina strangled. There was no cause to delay the matter longer. He had word from Rome of the capture of Cardinal Orsini, of Gianbattista da Virginio, of Giacomo di Santacroce, and Rinaldo Orsini, Archbishop of Florence.
On January 27, Pandolfo Petrucci being still in Siena, and Cesare's patience exhausted, he issued an ultimatum from his camp at Sartiano in which he declared that if, within twenty four hours, Petrucci had not been expelled from the city, he would loose his soldiers upon Siena to devastate the territory, and would treat every inhabitant " as a Pandolfo and an enemy."
Siena judged it well to bow before that threatening command, and Cesare, seeing himself obeyed, was free to depart to Rome, whither the Pope had recalled him and where work awaited him. He was required to make an end of the resistance of the barons, a task which had been entrusted to his brother Giuffredo, but which the latter had been unable to carry out.
In this matter Cesare and his father are said to have violently disagreed, and it is reported that high words flew between them; for Cesare who looked ahead and had his own future to consider, which should extend beyond the lifetime of Alexander VI would not move against Silvio Savelli in Palombara, nor Gian Giordano in Bracciano, alleging, as his reason for the latter forbearance, that Gian Giordano, being a knight of St. Michael like himself, he was inhibited by the terms of that knighthood from levying war upon him. To that he adhered, whilst disposing, however, to lay siege to Ceri, where Giulio and Giovanni Orsini had taken refuge.
In the meantime, the Cardinal Gianbattista Orsini had breathed his last in the Castle of Sant' Angelo.
Soderini had written ironically to Florence on February 15 : " Cardinal Orsini, in prison, shows signs of frenzy. I leave your Sublimities to conclude, in your wisdom, the judgment that is formed of such an illness."
It was not, however, until a week later on February 22 that he succumbed, when the cry of " Poison! " grew so loud and general that the Pope ordered the cardinal's body to be carried on a bier with the face exposed, that all the world might see its calm and the absence of such stains as were believed usually to accompany venenation.
Nevertheless, the opinion spread that he had been poisoned and the poisoning of Cardinal Orsini has been included in the long list of the Crimes of the Borgias with which we have been entertained. That the rumour should have spread is not in the least wonderful, considering in what bad odour were the Orsini at the Vatican just then, and be it remembered what provocation they had given. Although Valentinois dubbed Pandolfo Petrucci the "brain" of the conspiracy against him, the real guiding spirit, there can be little doubt, was this Cardinal Orsini, in whose stronghold at Magione the diet had met to plot Valentinois's ruin the ruin of the Gonfalonier of the Church, and the fresh alienation from the Holy See of the tyrannies which it claimed for its own, and which at great cost had been recovered to it.
Against the Pope, considered as a temporal ruler, that was treason in the highest degree, and punishable by death ; and, assuming that Alexander did cause the death of Cardinal Orsini, the only just censure that could fall upon him for the deed concerns the means employed. Yet even against that it might be urged that thus was the dignity of the purple saved the dishonouring touch of the hangman's hands.
Some six weeks later on April 10 died Giovanni Michieli, Cardinal of Sant' Angelo, and Giustiniani, the Venetian ambassador, wrote to his Government that the cardinal had been ill for only two days, and that his illness had been attended by violent sickness. This and the reticence of it was no doubt intended to arouse the suspicion that the cardinal had been poisoned. Giustiniani adds that Michieli's house was stripped that very night by the Pope, who profited thereby to the extent of some 150,000 ducats, besides plate and other valuables ; and this was intended to show an indecent eagerness on the Pope's part to possess himself of that which by the cardinal's death he inherited, whereas, in truth, the measure would be one of wise precaution against the customary danger of pillage by the mob.
But in March of the year 1504, under the pontificate of Julius II (Cardinal Giuliano della Rovere) a sub deacon, named Asquino de Colloredo, was arrested for defaming the dead cardinal (" interfector bone memorie Cardinalis S. Angeli "J.1 What other suspicions were entertained against him, what other revelations it was hoped to extract from him, cannot be said ; but Asquino was put to the question, to the usual accompaniment of the torture of the cord, and under this he confessed that he had poisoned Cardinal Michieli, constrained to it by Pope Alexander VI and the Duke of Valentinois, against his will and without reward (" verumtamen non voluisse et pecunias non habuisse ").