The story of the expedition of the Argonauts is very old.
It was there that they placed the scene of the sufferings of Prometheus (vide Aeschylus, Prometheus Vinctus), and there, in the land of Colchis, which corresponds to the valley of the Rion, that they sent the Argonauts to fetch the golden fleece.
On the arrival of the Argonauts, Phineus promised to give them particulars of the course they should pursue and of the dangers that lay before them, if they would deliver him from his tormentors.
After Cyzicus had been duly mourned and buried, the Argonauts proceeded along the coast of Mysia, where occurred the incident of Heracles and Hylas.
He knew the course to Colchis, and offered to tell it, if the Argonauts would free him from the Harpies.