These two important interests, compromised by the Duke of Milan's proposition, changed the whole face of Italy.
Ludovico Sforza had already made sure of Ferdinand's promise to conform to the plan he had invented, when the old king, at the solicitation of Piero, suddenly drew back.

Sforza found out how this change had come about, and learned that it was Piero's influence that had overmastered his own.

He could not disentangle the real motives that had promised the change, and imagined there was some secret league against himself: he attributed the changed political programme to the death of Lorenzo dei Medici.

But whatever its cause might be, it was evidently prejudicial to his own interests: Florence, Milan's old ally, was abandoning her for Naples.

He resolved to throw a counter weight into the scales; so, betraying to Alexander the policy of Piero and Ferdinand, he proposed to form a defensive and offensive alliance with him and admit the republic of Venice; Duke Hercules III of Ferrara was also to be summoned to pronounce for one or other of the two leagues.