The Metamorphoses of Ovid, Books VIII-XV

The river Acheloüs, which ran between Acarnania and Ætolia, often did considerable damage to those countries by its inundations, and, at the same time, by confounding or sweeping away the limits which separated those nations, it engaged them in continual warfare with each other. Hercules, who seems really to have been a person of great scientific skill, which he was ever ready to employ for the service of his fellow men, raised banks to it, and made its course so uniform and straight, that he was the means of establishing perpetual peace between these adjoining nations.

The early authors who recorded these events have narrated them under a thick and almost impenetrable veil of fiction. They say that Hercules engaged in combat with the God of that river, who immediately transformed himself into a serpent, by which was probably meant merely the serpentine windings of its course. Next they say, that the God changed himself into a bull, under which allegorical form they refer to the rapid and impetuous overflowing of its banks, ever rushing onwards, bearing down everything in its course, and leaving traces of its ravages throughout the country in its vicinity. This mode of description the more readily occurred to them in the case of Acheloüs, as from the roaring noise which they often make in their course, rivers in general were frequently represented under the figure of a bull, and, of course, as wearing horns, the great instruments of the havoc which they created.

It was said, then, that Hercules at length overcame this bull, and broke off one of his horns; by which was meant, according to Strabo, that he brought both the branches of the river into one channel. Again, this horn became the Horn of Plenty in that region; or, in other words, being withdrawn from its bed, the river left a large track of very fertile ground for agricultural purposes. As to the Cornucopia, or Horn of Plenty of the heathen Mythology, there is some variation in the accounts respecting it. Some writers say that by it was meant the horn of the goat Amalthea, which suckled Jupiter, and that the Nymphs gave it to Acheloüs, who again gave it in exchange for that of which Hercules afterwards deprived him. Deïanira, having given her hand to Hercules, as the recompense of the important services which he had rendered to her father, Œneus, it was fabled that she had been promised to Acheloüs, who was vanquished by his rival; and on this foundation was built the superstructure of the famous combat which the Poet here describes. After having remained for some time at the court of his father-in-law, Hercules was obliged to leave it, in consequence of having killed the son of Architritilus, who was the cupbearer of that prince.