ÆGOS POTAMOS, (anc. geogr.) a river in the Thracian Chersonesus, falling with a south-east course into the Hellespont, to the north of Sestos; also a town, station, or road for ships, at its mouth. Here the Athenians, under Conon, through the fault of his colleague Isocrates, received so fatal a blow from the Lacedæmonians under Lysander, in a sea-engagement, as to cost them their liberty and their all.