Agathocles

Agathocles (Greek: Ἀγαθοκλῆς; born between 320–310s BC-died 284 BC) was a Greek Prince who was of Macedonian and Thessalian descent. He was the son born to Lysimachus from his first wife the Queen consort, Nicaea a daughter of the powerful regent Antipater. His full blooded siblings were his younger sisters:Eurydice and Arsinoe I.

Agathocles was sent by his father against the Getae, about 292 BC, but was defeated and taken prisoner. He was kindly treated by Dromichaetes 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 Dromichaetes, 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.

In 287 BC Agathocles was sent by his father against Demetrius I Poliorcetes, who had marched into Anatolia to deprive Lysimachus of Lydia and Caria. In this expedition he was successful; he defeated Demetrius I and drove him out of his father's provinces. Agathocles was destined to be the successor of Lysimachus, and was popular among his subjects. His stepmother Arsinoe II, prejudiced the mind of his father against him and after an unsuccessful attempt to poison him, Lysimachus cast him into prison and had him executed (284 BC). His maternal cousin-wife and now widow Lysandra with their children fled with Alexander (Agathocles' paternal half-brother) to Seleucus I Nicator in Syria, who made war upon Lysimachus in consequence.

Louis Robert has suggested that coins ΑΓΑΘ of 300 BC belong to an Agathocleia city in Mysia founded by Agathocles.

Source :

https://en.wikipedia.org/wiki/Agathocles_(son_of_Lysimachus)