The Petrucci conspiracy was an obscure and vicious affair that has baffled everyone from that day to this. Leo professed to discover through betrayal by a servant a conspiracy of several cardinals to assassinate him. Led by the young Cardinal Alfonso Petrucci of Siena, who nursed a personal grievance, the plot depended on poison to be injected by a suborned doctor in the course of lancing a boil on the Pope’s buttock.
