2. A Corinthian captain, who in the eighteenth year of the Peloponnesian war, B. C. 414, took charge of a single ship of reinforcements for Syracuse. He left Leucas after Gylippus, but, sailing direct for Syracuse itself, arrived there first. It was a critical juncture: the besieged were on the point of holding an assembly for discussion of terms of surrender. His arrival, and his news of the approach of Gylippus, put a stop to all thought of this; the Syracusans took heart, and presently moved out to support the advance of their future deliverer. Thucydides seems to regard this as the moment of the turn of the tide. On the safe arrival of Gongylus at that especial crisis depended the issue of the Sicilian expedition, and with it the destiny of Syracuse, Athens, and all Greece. Gongylus fell, says Plutarch, in the first battle on Epipolae, after the arrival of Gylippus. (Thuc. 7.2; Plut. Nicias, 19.)
[A.H.C]A Dictionary of Greek and Roman biography and mythology
Smith, William
A Dictionary of Greek and Roman biography and mythology. William Smith, LLD, ed. 1890