2. King of Thrace from B. C. 382 to 358. (See Suid. s.v. where his reign is said to have lasted twenty-four years.) It is not, however, till towards the end of this period that we find anything recorded of him. In B. C. 364 he appears as an enemy of the Athenians, the main point of dispute being the possession of the Thracian Chersonesus, and it was at this time that he first availed himself of the aid of the adventurer Charidemus on his desertion from the Athenian service [see p. 684b.]. He also secured the valuable assistance of Iphicrates, to whom he gave one of his daughters in marriage, and who did not scruple to take part with his father-in-law against his country. (Dem. c. Aristocr. pp. 663, 669, 672; Pseudo-Aristot. Econ. 2.26; Nep. Iphicr. 3; Anaxandr. apud Athen. iv. p. 131.) In B. C. 362, Miltocythes, a powerful chief, revolted from Cotys, and engaged the Athenians on his side by promising to cede the Chersonesus to them; but Cotys sent them a letter, outbidding his adversary in promises, and the Athenians passed a decree in the king's favour. It has been thought that this was the same decree which conferred on him the gift of citizenship. (See Thirlwall's Greece, vol. v. p. 217; Ep. Phil. ad Ath. p. 161, where he is called " Sitalces.")
A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890
870
The effect of it certainly was so to discourage Miltocythes that he abandoned the struggle, while Cotys, having gained his point, never dreamed of fulfilling his promises. (Dem. c. Aristocr. p. 655, c. Polycl. 1207.) [AUTOCLES, No. 2.] In the same year he vigorously opposed Ariobarzanes and the other revolted satraps of the western provinces. Here again he shewed his hostility to Athens, which sided with the rebels, while another motive with him for the course he took seems to have been, that the satraps protected the cities on the Hellespont, over which he desired to establish his own authority. Having besieged Sestus, which belonged to Ariobarzanes, he was compelled, apparently by Timotheus, to raise the siege; but the town soon after revolted from Athens and submitted to Cotys, who, having in vain tried to persuade Iphicrates to aid him [IPHICRATES], again bought the services of Charidemus, made him his son-in-law, and prosecuted the war with his assistance. (Xen. Ages, 2.26; Nep. Timoth. 1; Dem. de Rhod. Lib. p. 193, c. Aristocr. pp. 663, 664, 672-674.) [CHARIDEMUS.] This appears to have occurred in B. C. 359, and in the same year, and not long after Philip's accession, we find him supporting the claims of the pretender Pausanias to the Macedonian throne; but the bribes of Philip induced him to abandon his cause. (Diod. 16.2, 3.) For his letter to Philip, perhaps on this occasion, see Hegesand. apud Athen. vi. p. 248. In B. C. 358, he was assassinated by Python or Parrhon and Heracleides (two citizens of Aenus, a Greek town in Thrace), whose father he had in some way injured. The murderers were honoured by the Athenians with golden crowns and the franchise of the city. (Arist. Polit. 5.10, ed. Bekk.; Dem. c. Aristocr. pp. 659, 662, 674 ; Plut. ad v. Colot. 32; D. L. 3.46, 9.65.) Cotys, from the accounts we have of him, was much addicted to gross luxury, and especially to drunkenness, the prevalent vice of his nation. His violence and cruelty were excessive, almost, in fact, akin to madness. He is said to have murdered his wife, of whom he was jealous, with circumstances of the most shocking barbarity; on one occasion also he persuaded himself, or chose to assert, that he was the bridegroom of the goddess Athena, and, having drunk deeply at what he called the nuptial feast, he put to death two of his attendants successively, who had not presence of mind or courtly tact sufficient to fall in with his mad humour. (Theopomp. apud Athen. xii. pp. 531, 532; Suid. s.v. Plut. Reg. et Imp. Apophth.)