Oeniadae or Oiniadai (Ancient Greek: Οἰνιάδαι), or Oeneiadae or Oineiadai (Οἰνειάδαι), was a town in ancient Acarnania, situated on the west bank of the Achelous River, about 10 miles (16 km) from its mouth. It was one of the most important of the Acarnanian towns, being strongly fortified both by nature and by art, and commanding the whole of the south of Acarnania. It was surrounded by marshes, many of them of great extent and depth, which rendered it quite inaccessible in the winter to an invading force. Its territory appears to have extended on both sides of the Achelous, and to have consisted of the district called Paracheloitis, which was very fertile. It seems to have derived its name from the mythical Oeneus, the great Aetolian hero.
The town is first mentioned about 455 BCE. The Messenians, who had been settled at Naupactus by the Athenians at the end of the Third Messenian War, shortly afterwards made an expedition against Oeniadae, which they took; but after holding it for a year, they were attacked by the Acarnanians and compelled to abandon the town. Oeniadae is represented at that time as an enemy of Athens, which is said to have been one of the reasons that induced the Messenians to attack the place. Twenty-three years before the Peloponnesian War (454 BCE) Pericles laid siege to the town, but was unable to take it. In the Peloponnesian War, Oeniadae still continued opposed to the Athenians, and was the only Acarnanian town, with the exception of Astacus, which sided with the Lacedaemonians. In the third year of the war (429 BCE) Phormion made an expedition into Acarnania to secure the Athenian ascendancy; but though he took Astacus, he did not continue to march against Oeniadae, because it was the winter, at which season the marshes secured the town from all attack. In the following year (428 BCE) his son Asopius sailed up the Achelous, and ravaged the territory of Oeniadae; but it was not till 424 BCE that Demosthenes, assisted by all the other Acarnanians, compelled the town to join the Athenian alliance.
