 As the future tyrant of Syracuse, Dion, who was also a student of Plato, recruited Callippus as a member of his army which successfully invaded Syracuse.The army marched into Syracuse with 800 mercenaries and took control of the city, disposing of the previous tyrant, Dion’s nephew Dionysius II.In exile, Dionysius bribed Callippus to kill Dion, and Callippus accepted the offer.