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.