There abode in Thessaly, in the days of Hercules, a strange race of men who had the head and arms of a man together with the body of a horse. They were called Centaurs, or Bull-Slayers.
One of them named Cheiron, famous for his knowledge of medicine, music and botany, had been the teacher of Hercules. But many of them, although learned, were not good. Hercules and Theseus had waged war on them and had killed many, so that their numbers were greatly lessened.
Having married Deianira, the daughter of a powerful King of Calydon, in Greece, Hercules was traveling home with her when he came to the banks of a river and was at a loss how to cross it. Seeing his perplexity, Nessus, one of the Centaurs, offered to take Deianira on his back and carry her over the stream. This offer Hercules gladly accepted.
No sooner, however, did the crafty Centaur obtain possession of Deianira than he made off with her, intending to have her as his own wife. You can easily imagine how angry this outrage made Hercules. He shot one of his poisoned arrows with so much force that it went right through the traitor Centaur, and wounded him even unto death.
But, before dying, Nessus had time to tell Deianira that if she wanted to keep Hercules always true to her she had but to take his shirt, and, when her husband's love was waning, prevail on him to wear it.
Deianira took the shirt, and shortly afterwards, being afraid that her husband was ceasing to love her, she sent it to him as a present.
Now, you will remember that Hercules had shot through the shirt of Nessus one of his poisoned arrows, and you will not be surprised to hear that some of the poison had remained in the shirt. So when Hercules put it on, which he did immediately upon receiving it, he was seized with frenzy and, in his madness, he uttered terrible cries and did dreadful deeds.
With his powerful hands he broke off huge pieces of rock, tore up pine-trees by their roots and hurled them with resounding din into the valley.
He could not take off the fatal shirt, and as he tore off portions of it he tore, at the same time, his quivering flesh.
The servant of Deianira who had carried him the fatal shirt, and who wished to solace him in his pain, he seized as she approached him and flung headlong into the sea, where she was changed into a rock that long, so runs the legend, kept its human form.