COTYS, a name common to several kings of Thrace. Of these the most important began to reign in 382 b.c. He was notorious both for cruelty and for drunkenness. Almost the whole of the information we possess of his reign is connected with his quarrels with the Athenians. The first of these was foi the Thracian Cheronese, in which Cotys was assisted by the Athenian Iphicrates, to whom ho had given his daughter in marriage. On the revolt of Ariobarzanes from Persia, Cotys opposed him and his ally, the Athenians. In 358 he was murdered by the sons of a man whom he had wronged, and the Athenians rewarded his assassins with golden crowns.