(Δέρδας), a prince of Elymia or Elimeia, and probably of the same family as the cousin of Perdiccas II. mentioned above. As he had reason, from the example of Amyntas II. [see p. 154b.], to fear the growing power of Olynthus, he zealously and effectually aided the Spartans in their war with that state, from B. C. 382 to 379. (Xen. Hell. 5.2, 3; Diod. 15.19-23.) We learn from Theopompus (apud Athen. x. p. 436d.), that he was taken prisoner by the Olynthians, but it does not appear on what occasion; nor is it certain whether he is the same Derdas to whom Aristotle alludes. (Polit. 5.10, ed. Bekk.) Derdas, whose sister Phila was one of the wives of Philip, was probably a different person, though of the same family. (Ath. xiii. p. 557c.)