[1] The son of Pleuratus II, Agron succeeded in reconquering southern Illyria, which had been under the control of Epirus since the time of Pyrrhus, and in extending Illyrian rule over many cities in the Adriatic region, including Corcyra, Epidamnos, and Pharos.
Agron was mentioned by two Greek historians, Appian (95–165 AD) in his Foreign Wars and Polybius (203–120 BC) in his Histories.
Besieged at Medion, the Acarnanians sought assistance from Demetrius II of Macedonia, who for the most of his reign had been at war with the Aetolian and Achaean Leagues.
The Illyrian attack under Agron, mounted in either 232 or 231 BC, is described by Polybius: One hundred lembi with 5000 men on board sailed up to land at Medion.
The latter were overwhelmed with astonishment at the unexpected nature and boldness of the move; but they had long been inspired with overweening self-confidence, and having full reliance on their own forces were far from being dismayed.
A single charge, however, of the Illyrians, whose numbers and close order gave them irresistible weight, served to dislodge the light-armed troops, and forced the cavalry who were on the ground with them to retire to the hoplites.
The Medionians joined the action by sallying out of the town and charging the Aetolians, thus, after killing a great number, and taking a still greater number prisoners, and becoming masters also of their arms and baggage, the Illyrians, having carried out the orders of Agron, conveyed their baggage and the rest of their booty to their boats and immediately set sail for their own country.
The Greek cities (poleis) on the coast of Illyria were systematically attacked and perhaps already conquered[clarification needed] by Agron's forces.