 Pandolfo slowly gathered many political offices and grew his influence until 1500, when with the execution of his father-in-law Niccolò Borghese for conspiracy to murder him, as well as with the support of Florence and of Alfonso of Calabria, Pandolfo was able to seize complete control of the city.Though a tyrant, Pandolfo brought Siena back to prosperity, favoring arts and sciences, as well as improving its economy.Pandolfo was succeeded by his son Borghese Petrucci.