Heracles came in early manhood to Pleuron in Aetolia, where Deianeira, daughter of the King Oeneus, was being wooed by the river-god Acheloüs; he overthrew the monstrous suitor in combat, and married the fair maiden. As he went away with his bride, they came to the river Evenus, where Nessus carried travellers across. While conveying Deianeira over, he insulted her, and Heracles shot him with an arrow. The dying Centaur said to her: 'Thou hast been my last passenger, and I would fain show thee a grace. Take some of the blood that is clotted about my wound: it will be a love-charm for the soul of Heracles, and thou shall never have cause to fear a rival.' And then he told her how to use it. This gift she secretly treasured.
The goddess Hera bore enmity to Heracles, as the son of her husband Zeus and Alcmena; and presently she made him a thrall to Eurystheus, king of Tiryns, who sent him on many perilous labours. Deianeira and her children now dwelt at Tiryns. There it befell that Heracles treacherously slew Iphitus, son of Eurytus, king of Oechalia in Euboea,—visiting the father's deed upon the son, for Eurytus had once done him a foul despite. Heracles and his family were then forced to leave Tiryns. A new home was given them at Trachis by the herd's kinsman, the good king Ceÿx. But Zeus was wroth with Heracles because he had slain Iphitus by guile; and doomed him to servitude under a barbarian mistress, the Lydian Omphale, for a year. So Heracles went away from Trachis, leaving his wife and children there: they did not know whither he had gone. When his year with Omphale was over, and he had been purged of blood-guilt, he fulfilled the oath that he had sworn to himself, to be avenged on Eurytus, the first cause of his dishonour. He gathered an army: he ravaged Oechalia with sword and fire; slew the king and the male folk; and sent a train of captive women to Trachis, among whom was Iole, the daughter of Eurytus.
It is at this moment that the play begins. Fifteen months have passed since Heracles left Trachis, and still Deianeira knows not where he is: she has not yet heard the news concerning Oechalia.
