The chronicles and diplomatic dispatches of the period report that Caterina Sforza is very enamored with her young lover and secret husband Giacamo Feo, and it is feared that she will give political precedence and power to him, passing over her eldest son and Riario's heir, Ottaviano.

These fears had lead to two failed conspiracies to assassinate Feo and Sforza.

The third conspiracy, organized by Giovanni Antonio Ghetti and some of Caterina's own children, finally succeeds in killing Feo on August 27, 1495, when he and Sforza and their entourage are returning to Forlì from a hunting trip.

Sforza and her daughter, Bianca, with some of her ladies-in-waiting, lead the group in a carriage, while Feo, along with Sforza's sons, Ottaviano and Cesare, and many staffieri and soldiers, follow on horseback.

As they approach the Schiavonia gate into Forlì, Feo is cut off from the others by the conspirators, stabbed and beaten to death.

Sforza escapes to the safety of Ravaldino.

The same day, Ghetti goes to Caterina, thinking that she had secretly given the order to kill Giacomo.

Caterina had been unaware of the plot, and her revenge is terrible.

When her first husband was murdered, she had avenged his death according to the justice of the time; now she reacts with vindictive fury.

Caterina is not satisfied with mere executions: their deaths have to be among the most cruel and painful.

She not only prosecutes the wives and mistresses of the conspirators, but she also seeks out the children, even those in early infancy, and all are summarily tortured and executed.

In all, thirty-eight people are executed for the crime—including Ghetti and his wife and children—and many others imprisoned or exiled.

Caterina's fury has blinded her to the politics that had inspired the plot.

It had involved almost all the supporters of Ottaviano Riario, who were convinced that Caterina had given her tacit consent to the killing of the man who was considered the "usurper" of the state's rightful ruler.

They had wanted to uphold the power of the Riario family.

Caterina, as a result of the massacre that follows the assassination of Giacomo Feo, has lost forever the good will of her people.