Lysimachus, a Greek general, king of Thrace, born in Pella, Macedonia, about 360 B. 0., slain in battle in 281. He was the son of Aga-thocles, a Thessalian, and was early distinguished for valor, activity, and bodily strength. On the division of the provinces, after the death of Alexander (323), Thrace and the region bordering on the Danube were allotted to him. In 315 he joined the coalition formed against Antigonus by Ptolemy, Seleucus, and Cassan-der. In 306 he assumed the title of king. In 302 he invaded Asia Minor, overran Phrygia, and reduced several of the Hellespontine cities. On the approach of Antigonus, however, he retired into Bithynia, where he was joined by Seleucus, and the two confederates advanced in the spring of 301 against Antigonus and his son Demetrius. At the battle of Ipsus, which ensued soon after, Lysimachus and Seleucus, aided by the forces of Ptolemy and Cassander, completely vanquished their antagonists, and shared between them the dominions of Antigonus. Of the territory which accrued to the king of Thrace in consequence of this victory, he retained possession almost until his death, rebuilding the cities in it that had been ruined during the war, and so improving and enlarging New Ilium and the Mysian Alexandria that he came to be regarded as their founder.
In 292 he undertook an expedition against the Getae north of the lower Danube, and was compelled by famine to surrender with his whole army, but was soon set at liberty. In 288 he formed a confederacy with Ptolemy, Seleucus, and Pyrrhus against Demetrius Poliorcetes (who had invaded Thrace during his absence and captivity), the result of which was that the latter lost his kingdom of Macedonia, and that Lysimachus presently got possession of it. Having consented to the death of his son Agathocles at the instigation of Arsinoe, daughter of Ptolemy, whom he had recently married, his Asian subjects rebelled; and Seleucus, to whose court the widow of Agathocles had fled, marched to their aid. The hostile monarchs (the two last survivors of the generals of Alexander, and both almost octogenarians) met on the plain of Corus, in Phrygia, and in the battle which ensued Lysimachus was defeated and slain.