Sitalces was succeeded in 424 by his nephew Seuthes I after the former was killed while campaigning against the Triballi, who resided north of the western Haemus. Throughout his reign, the Odrysians did not inteverne in coastal Thrace, which had now become a contested battlefield between Athens and Sparta. Athens for its part began to make heavy use of Thracian mercenaries acting as light skirmishers, the peltasts. Due to their success the Greeks soon began to raise peltast units of their own. Still, the Athenians eventually lost the Peleponnesian war and, for a few years at least, much of their influence in the northern Aegean. Seuthes I was eventually succeeded by Amadocus I, also known as Medokos, in around 410 or 405 BC.