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.

Rome, in response to the the robbery and murder of the Italian merchants in Phoenice by Illyrian pirates in 230 BCE, had sent ambassadors to the Adieaean kingdom’s queen Teuta, widow of Agros, and received a haughty reception from the militant queen.

The ambassadors had been ambushed and killed on their return through Illyria, causing the Senate to order vengeance against the Illyrians.

Greek allegations that the Illyrians are disrupting commerce and plundering coastal towns helps precipitate a Roman punitive strike in 229 BCE.

In the first action of the Illyrian War, the Romans relieve Corcyra, used as a port by Roman ships and currently besieged by the Illyrians, with little or no fighting.

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 …