8. Son of Lysimachus, king of Thrace. He was the eldest of the three sons of that monarch by his last wife Arsinoe, and the only one who escaped falling into the hands of Ptolemy Ceraunus. Having in vain urged his mother not to trust to the friendly professions of the usurper, he himself appears to have made his escape and taken refuge with Monunius, king of the Dardanians, whom he persuaded to take up arms in his cause, but we know nothing of the events of the war. (Just. 24.2; Trog. Pomp. Prol. xxiv.) It is probable, however, that the Ptolemy who is mentioned as establishing, or asserting, a transient claim to the throne of Macedonia, during the period of anarchy which followed the death of Ptolemy Ceraunus (B. C. 280-277), is no other than the one in question. (Porphyr. apud Euseb. Arm. p. 157; Dexippus, apud Syncetl. p. 267.)