Prusias I of Bithynia has formed a marriage alliance with Demetrius II of Macedon; he will eventually receive the latter's daughter, Apama III, as his wife.

His elder sister, born around 245 BCE, is married to the Seleucid prince Anthiochus Hierax.

Attalus follows his victory over the Gauls by defeating Antiochus Hierax, the rebellious Seleucid prince, in the first of three battles for primacy in Anatolia.

The revolution in Epirus, which has substituted a republican league for the monarchy, has gravely weakened the position of Demetrius, who has hired Agron, king of the Ardiaean Kingdom of Illyria, for military aid against the advancing Aetolians.

His kingdom is not threatened by the Ardiaei, despite them having gathered the greatest force in their history, but Epirus needs some sort of force to deter them.

Demetrius must also defends his domain from the tribal peoples of the north.

Thus threatened, he is drawn northward by a Dardanian invasion, and after a defeat there, he dies in 229-228, leaving as his heir Philip, his son by Chryseis, still a child.

Upon Demetrius’ death, the War of Demetrius ends and a regency is established for his eight-year-old son under his cousin, Antigonus Doson.

Information regarding the life of Demetrius is drawn mainly from inscription as only Plutarch writes of him, in Life of Aratus; Polybius makes scarce mentions of him.

Aratus of Sicyon brings Argos into the Achaean League in 229 BCE and …

…helps liberate Athens from Macedonian rule.

The Achaean League's gains in the Peloponnesus are threatened by the hostility of Sparta, ruled from 235 by Cleomenes III, whose wife (Agis' widow), has won him to the need for nationalist revolution.

In this, she has had the support of Cleomenes' stoic tutor Sphaerus, who seems to have read a remarkable utopian narrative composed around 250 by an otherwise obscure author named Iambulus.

Attalus, ostensibly a vassal-ally of the dominant Seleucid dynasty to which he is distantly related, proves both a strong protector of the Greek cities of Anatolia and an opportunist in trying to expand Pergamon's territory and power.

In expelling Hierax from Anatolia in 228, Attalus thereby gains control over all the Seleucid domains in Anatolia except Cilicia in the southeast, which Ptolemy III has successfully wrested from the Seleucids.

Queen Teuta surrenders to Rome in 228 BCE, giving up her land claims and pledging indemnity payments.

The Romans ally with Macedon to ensure that Illyria’s flank is guarded.

The Achaean League, on commencing hostilities with Sparta in 228, allies itself with Rome.

Demetrius' failure has seriously weakened both kingdom and monarchy, but …