Aristodemus of Miletus (Greek: Ἀριστόδημος; lived 4th century BC) was one of the oldest and most trusted friends of Antigonus Monophthalmus.
[2] In 314 BC, Antigonus sent him to the Peloponnese with 1,000 talents, ordered him to maintain friendly relations with Polyperchon and his son Alexander, to collect as large a body of mercenaries, and to conduct the war against Cassander.
On his arrival in Laconia, he obtained permission from the Spartans to engage mercenaries in their country, and thus raised an army of 8,000 men in the Peloponnese.
After his departure, Aristodemus and Alexander at first endeavoured in common to persuade the towns to expel the garrisons of Cassander, and recover their independence.
But Alexander soon allowed himself to be made a traitor to the cause he had hitherto espoused, and was rewarded by Cassander with the chief command of his forces in the Peloponnese.
[6] Aristodemus landed from his ship alone and refused to give any indication of the news he bore, he advanced slowly to the royal palace, gathering a large crowd.