According to ancient Greek mythology, Aeson was the rightful king of Iolcus, but his half-brother Pelias usurped the throne.

The ship Argo set sail from Iolcus with a crew of fifty demigods and princes under Jason's leadership.

Their mission was to reach Colchis in Aea at the eastern seaboard of the Black Sea and to reclaim and bring back the Golden Fleece.

Along with the Golden Fleece, Jason brought a wife, the sorceress Medea—king Aeetes' daughter, granddaughter of Helios, niece of Circe, princess of Aea, and later queen of Iolcus, Corinth and Aea, and also murderer of her brother Absyrtus, and her two sons from Jason.

She is a tragic figure whose trials and tribulations were artfully dramatized in the much-staged play by Euripides, Medea.

Iolcus is mentioned by Homer, in the Catalogue of Ships in the Iliad, and later in the Odyssey; he gives it the epithets of ἐϋκτιμένη ("well built") and εὐρύχορος ("with broad places", "spacious").