However when, later in the year, Ambracia invades Acarnania, and the Acarnanians seek help from Demosthenes, who is patrolling the Ionian Sea coast with twenty Athenian ships, he reaches the Athenian naval base in the Gulf of Corinth at Naupactus and secures it just in time to defend it against a large Spartan army from Delphi under Eurylochus which has come to assist the Ambraciots.
The earliest historical person who probably belongs to the Aleuadae is the general Eurylochus, who terminated the First Sacred War about 590 BC.
In 426 BC, Spartan general Eurylochus, on his way to Naupactus, arrived to Delphi and sent a herald to Amfissa, in order to detach them from Athens and make the Amfissians leave him pass through their lands.
It went on a rampage, and was driven away or captured by Eurylochus, who gifted it to Demeter, a goddess who then kept it for her own.
Polyaenus also gave credit for the strategy not to Kleisthenes but to General Eurylochus, who he claimed advised his allies to gather a large amount of hellebore from Anticyra, where it was abundant.
Diogenes Laertius (ix.61) relates that he was a student of Pyrrho, along with Eurylochus, Timon the Phliasian, Nausiphanes of Teos and others, and includes him among the "Pyrrhoneans".