4. A son of Dionysius tyrant of Heracleia and of Amastris, the daughter of No. 2. He succeeded, together with his brother Cledrchus, to the sovereignty of Heracleia on the death of Dionysius, B. C. 306 : but the government was administered by Amastris during the minority of her two sons. Soon after the young men had attained to manhood and taken the direction of affairs into their own hands, they caused their mother to be put to death : but this act of parricide brought upon them the vengeance of Lysimachus, who made himself master of Heracleia, and put both Clearchus and Oxathres to death. According to Diodorus, they had reigned seventeen years; but Droysen assigns their death to the year B. C. 285. (Memnon, 100.4-6; Diod. 20.77; Droysen, Hellenism. vol. i. pp. 609, 634.)