2. The son of Lysimachus by an Odrysian woman, whom Polyaenus (6.12
) calls Macris. Agathocles was sent by his father against the Getae, about B. C. 292, but was defeated and taken prisoner.
He was kindly treated by Dromichaetis, the king of the Getae, and sent back to his father with presents; but Lysimachus, notwithstanding, marched against the Getae, and was taken prisoner himself.
He too was also released by Dromichaetis, who received in consequence the daughter of Lysimachus in marriage.
According to some authors it was only Agathocles, and according to others only Lysimachus, who was taken prisoner. (Diod. Exc.
xxi. p. 559, ed. Wess.; Paus. 1.9.7
; Strab. vii. pp. 302, 305; Plut. Demetr. c. 39
, de ser. num. vind.
p. 555d.) In B. C. 287, Agathocles was sent by his father against Demetrius Poliorcetes, who had marched into Asia to deprive Lysimachus of Lydia and Caria.
In this expedition he was successful; he defeated Lysimachus and drove him out of his father's provinces. (Plut. Demetr. c. 46
.) Agathocles was destined to be the successor of Lysimachus, and was popular along his subjects; but his step-mother, Arsinoe, prejudiced the mind of his father against him; and after an unsuccessful attempt to poison him, Lysimachus cast him into prison, where he was murdered (B. C. 284) by Ptolemaeus Ceraunus, who was a fugitive at the court of Lysimachus. His widow Lysandra fled with his children, and Alexander, his brother, to Seleucus in Asia, who made war upon Lysimachus in consequence. (Memnon, apud Phot.
Cod. 124, pp. 225, 226, ed. Bekker; Paus. 1.10
; Justin, 17.1