Hellenic culture heavily influences the Getae, especially the ruling class, from about 300 BCE.

One Basileus Dromichaites, having organized the Getae of the Lower Danube into a state by about 300 BCE, repulses an attack by Lysimachus.

Hereafter, native Getian leaders protect the coastal urban centers that have developed from Greek colonies.

Agathocles is sent by his father against the Getae in about 292 BCE but is defeated and taken prisoner.

He is kindly treated by Dromichaetes, and sent back to his father with presents; but Lysimachus, notwithstanding, marches against the Getae, and is taken prisoner himself.

He too is 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.

Agathocles in 287 BCE is sent by his father against Demetrius I Poliorcetes, who has marched into Anatolia to deprive Lysimachus of Lydia and Caria.

He is successful in this expedition, defeating Demetrius I and driving him out of his father's provinces.

Ptolemy I Soter now dominates Cyprus, Phoenicia and Palestine.

He abdicates the throne of Egypt and Libya in 285 (possibly on June 26) in favor of his son by Berenice, Ptolemy II Philadelphus, who had in 289 been made made coregent.

His eldest (legitimate) son, Ptolemy Keraunos, whose mother, Eurydice, the daughter of the Alexandrine regent Antipater, had been repudiated, flees to the court of Lysimachus, the king of Thrace, Macedon, and part of Asia Minor, who is married to Ptolemy’s half-sister, Arsinoe.

The last period of Lysimachus' life is darkened by the intrigues of Arsinoe, his third wife and the daughter of Ptolemy I. Lysimachus had renamed Ephesus after her and given her three cities on the Black Sea, as well as Cassandreia, a city in northern Greece.

She strives to secure the succession of the Thracian kingdom for the eldest of her three sons by accusing the heir apparent, Agathocles, the king's eldest son by an earlier marriage, of conspiring with Seleucus to commit treason.

Agathocles is popular among his subjects, but his stepmother has prejudiced the mind of his father against him and after an unsuccessful attempt to poison him, the old and suspicious king orders him executed and casts him into prison, where he is murdered.

Philetaerus, governor of Pergamon, an ally of Agathocles in Asia Minor, also requests aid from Seleucus.