The siege triggered an invasion by an Illyrian relief force and ended in the Battle of Medion with an Aetolian defeat.
The king of Macedon Demetrius II Aetolicus, a rival of the Aetolian League, being himself engaged against the Dardanians, requested Agron of Illyria to intervene and help the Acarnanians.
[1][6][8] A modern historian, Erich S. Gruen, says that the fact that Demetrius of Macedon had to call the Illyrians to relieve Medion shows that he was incapable of doing so himself.
Polybius, on the other hand, who wrote a contemporary report, simply states that Agron was bribed by Macedon to attack the Aetolians.
The Illyrians landed on the Acarnanian coast in September and marched to Medion to attack the Aetolian besiegers.