Demophanes

Demophanes of Megalopolis, Platonic philosopher, and a disciple of Arcesilas. (Plut. Philopoem. 1.) He and Ecdemus of Arcadia were the chief persons who delivered Megalopolis from the tyranny of Aristodemus, and also assisted Aratus in abolishing tyranny at Sicyon. For a time (c. 250-246 BC ) they were entrusted with the administration of the state of Cyrene, and Philopoemen in his youth had enand joyed their friendship.

Plutarch, Philopoemen:

Once Philopoemen left the years of childhood, his teachers were Ecdemus and Demophanes. These two men were scholars of the Academy, and they had put their philosophical principles into practice by ending the tyranny of Aristodemus in the city of Megalopolis. They had also helped Aratus to expel the tyrant Nicocles from Sicyon. Of all their glorious achievements, Ecdemus and Demophanes considered that the education of Philopoemen was among the best.

Polybius

William Smith. A dictionary of Greek and Roman biography and mythology. London. John Murray. 1873