Hercules, upon completion of his celebrated Labors, "married Deianeira, and lived in peace with her three years. On one occasion as he was travelling with his wife, they came to a river across which the centaur Nessus carried travellers for a stated fee. Hercules himself founded the river, but gave Deianeira to Nessus to be carried across. Nessus attempted to run away with her but Hercules heard her cries, and shot an arrow into the heart of Nessus. The dying centaur told Deianeira to take a portion of his blood and keep it, as it might be used as a charm to perserve the love of her husband." Actually a poison, it ultimately caused the death of Hercules when he downned a garment unwittingly steeped in the blood. Bulfinch, The Age of Fable