(Σιτάλκης).
1. king of Thrace, or rather of the powerful Thracian tribe of the Odrysians, was a son of Teres, whom he succeeded on the throne. His father had already transmitted to him a powerful and extensive monarchy [TERES], but he himself increased it still farther by successful wars, so that his dominions ultimately comprised the whole territory from Abdera to the mouths of the Danube, and from Byzantium to the sources of the Strymon (Thuc. 2.29, 97; Diod. 12.50). The date of his accession is unknown, but it seems certain that Diodorus (l.c.) is in error in representing it as immediately preceding the Peloponnesian War : and Sitalces must at that period have been long seated on the throne, as he had already raised his power to the height of greatness at which we then find it. It was in the first year of that war (B. C. 431) that he was persuaded by Nymphodorus the son of Pythes, a citizen of Abdera, whose sister he had married, to enter into an alliance with Athens (Thuc. 2.29); and in the following year he showed his zeal in support of his new allies, by seizing and giving up to the Athenians the Corinthian and Lacedaemonian ambassadors, who had repaired to his court on their way to Asia to ask assistance of the king of Persia (Hdt. 7.137; Thuc. 2.67). The Athenians, on their part, appear to have cultivated his friendship by repeated embassies, which were received in the most friendly manner, both by the king himself and his son Sadocus, who had been admitted to the rights of Athenian citizenship (Thuc. l.c. ; Aristoph. Ach. 134_150, and Schol. ad loc.). The great object of the Athenians was to obtain the powerful assistance of Sitalces against Perdiccas, king of Macedonia, with whom the Thracian monarch was already on terms of hostility on account of the support which the latter had afforded or promised to Philip, the brother of Perdiccas. The Macedonian king had for a time bought off the hostility of his powerful neighbour by large promises, but these had never been fulfilled, and Sitalces now determined at once to avenge himself and support his Athenian allies, by invading the dominions of Perdiccas. The army which he assembled for this purpose was the most numerous that had been seen in Greece since the Persian invasion, amounting to not less than 50,000 horse and 100.000 foot. With this mighty host he crossed the passes of Mount Cercine, in the autumn of B. C. 429, and descended to Doberus in Paeonia. Perdiccas was wholly unable to oppose him in the field, and allowed him to ravage the open country, almost without opposition, as far as the river Axius. From thence he advanced through Mygdonia into Chalcidice, laying waste every thing on his passage. But he was disappointed of the expected co-operation of an Athenian fleet, and his vast army began to suffer from want of provisions and the approach of winter, so that he was induced to listen to the representations of his nephew Seuthes (who had been secretly gained over by Perdiccas), and withdrew into his own dominions, after having remained only thirty days in Macedonia. (Thuc. 2.95_101 ; Diod. 12.50, 51.)
Of the remaining events of his reign we have scarcely any information. We learn, indeed, that he was at one time on the eve of a war with the Scythians, in support of Scyles, king of that country, who had taken refuge with him [SCYLES]: but hostilities were prevented by a treaty between Sitalces and Octamasades, who had been chosen king by the Scythians, and who was himself son of a sister of the Thracian monarch. Sitalces consented to give up the fugitive Scyles, in exchange for a brother of his own, who had taken refuge with Octamasades (Hdt. 4.80). But the date of these events is wholly uncertain, and we know not whether they occurred previously or subsequent to the great expedition of Sitalces into Macedonia. The last event of his reign was an expedition against the Triballi, in which he engaged in B. C. 424, but was totally defeated, and himself perished in the battle. (Thuc. 4.101.)