[4] According to linguist Ivan Duridanov [bg], the Thracian river name Achelōos (alternatively, Achēlon and Achelon), located near Anchialo, in the Black Sea, is cognate to the Greek word, both deriving from a Proto-Indo-European stem *ɘku̯el, meaning 'water'.
[25] The story of Achelous, in the form of a bull, battling with Heracles for Deianeira, was apparently told as early as the 7th century BC, in a lost poem by the Greek poet Archilochus, while according to a summary of a lost poem by the early 5th-century BC Greek poet Pindar, during the contest, Heracles broke off one of Achelous's bull-horns, and the river-god was able to get his horn back by trading it for a horn from Amalthea.
[26] Sophocles, in his play Women of Trachis (c. 450–425 BC), has Deianeira tell her story, how Achelous wooed her in the shape of a bull, a snake, and a half-man/half-bull:[27] For my suitor was a river-god, Achelous, who in three shapes was always asking me from my father—coming now as a bull in visible form, now as a serpent, sheeny and coiled, now ox-faced with human trunk, while from his thick-shaded beard wellheads of fountain-water sprayed.
[31] According to Strabo, in some versions of the story Heracles gave Achelous's horn to Deianeira's father Oeneus as a wedding gift.
In this way, Heracles defeated the raging river, and in so doing created a large amount of new fertile land and "certain poets, as we are told, have made this deed into a myth" (Diodorus).
[37] Achelous played a role in the story of the Argive hero Alcmaeon, who had killed his mother Eriphyle because of her treachery against his father Amphiaraus, and needed to be religiously purified.
As Thucydides tells the story, the oracle of Apollo told Alcmaeon that he needed to find a land to live in that did not yet exist at the time of his mother's death.
[40] Ovid, in his Metamorphoses, has the river-god involved in two transformation stories concerning the creation of islands near the mouth of the Achelous River.
There my flood and the sea, united, cleft the undivided ground into as many parts as now you see the Echinades yonder amid the waves.
having no admixture of AchelousOvid, in his Fasti, uses Achelous' name as a stand in for water when he connects wine drinking with the wearing of flowers in the hair: No serious business does he do whose brow is garlanded; no water of the running brook is quaffed by such as twine their hair with flowers: so long as thy stream, Achelous, was dashed with no juice of grapes, none cared to pluck the rose.
[58] Hyginus explains that Oeneus was given the grape vine and instruction on viticulture by the wine-god, as a reward for his "generous hospitality" in having turned a blind eye to the god seducing his wife and fathering Deianeira.
[68] However some ancient scholars thought that the line: "nor the great might of deep-flowing Ocean", was spurious, which would in fact make Achelous—rather than Oceanus—the source of all other waters.
[69] A commentary on Iliad 21.195, preserved on Oxyrhynchus Papyrus 221, contains a fragment of a poem, possibly from the Epic tradition, which mentions "the waters of silver-eddying Achelous" being the source of "the whole sea".
[70] A late-5th-century BC commentary on an Orphic theogony, preserved by the Derveni Papyrus, quotes a poetic fragment calling the rivers the "sinews of Achelous".
[71] The same Oxyrhynchus Papyrus also quotes ancient verses which apparently equated Achelous and Oceanus,[72] and that "many people sacrifice to Achelois before sacrificing to Demeter, since Acheloios is the name of all rivers and the crop comes from water".
[83] Plato's Phaedrus has Socrates, walking in the countryside along the Ilissus river, come across a "sacred place of some nymphs and of Achelous, judging by the figurines and statues".
[88] This association is reflected in the fact that the Greeks depicted river-gods as part bull from at least the Archaic period onward.
[94] In these contexts, in which the identity of the figure as Achelous is secured by inscription,[95] the river-god is characteristically portrayed in the form of a man-bull, i.e. a bull with a bull-horned and bull-eared human face, head or torso and a bison-like beard, either in full-figure, or in the abbreviated form of a man-bull torso, head or particularly a mask.
[100] Possibly the earliest version of the scene (c. 600–560 BC) appears on the figure frieze of a Middle Corinthian kylix cup (Brussels A1374), which depicts Heracles wrestling with a horned centaur-like Achelous, with a human torso and a bull's or horse's body, watched by the figure of an old man (Oineus?)
[101] The earliest (c. 570 BC) Attic versions (New York 59.64, Boston 99.519) depict Achelous as a bull with a man's head and beard.
[104] On one later example (c. 525–475 BC), an Attic red-figure stamnos from Cerveteri attributed to Oltos (British Museum E437), Achelous (identified by inscription) is shown with a bearded human upper torso, attached to a long serpentine body, with a fish's tail.
[112] Three marble Attic reliefs (Athens 1445, 1448, and 1859) have the form of a cave, with four central figures, a male leading three nymphs, all holding hands gathered around a small stone altar (dancing?).
[116] In addition to vase paintings, votive reliefs, and coins, man-bull depictions can also be found on many other kinds of artifacts, including gems,[117] jewelry,[118] bronzes,[119] and architectural terracottas.
[121] A recent study has tried to show that both the form and substance of Achelous, as a god of water primarily depicted as a man-faced bull, have roots in Old Europe in the Bronze Age, and that after the disappearance of many Old European cultures, the traditions traveled to the Near East at the beginning of 4th millennium BC (Ubaid period),[122] and finally migrated to Greece, Italy, Sicily, and Sardinia with itinerant sea-folk during the Late Bronze Age through the Orientalizing period.
[123] Although no single cult of Achelous persisted throughout all of these generations, the iconography and general mythos easily spread from one culture to another, and all examples of man-faced bulls are found around the area of the Mediterraneanan, suggesting some intercultural continuity.
[124] Achelous was also an important deity in the Etruscan religion,[125] intimately related to water as in the Greek tradition but also carrying significant chthonic associations.
Man-faced bull iconography was first adapted to represent Achelous by the Etruscans in the 8th century BC, and the Greeks later adopted this same tradition.
[130] The Achelous River rises in the Pindus mountains, flows into the Ionian Sea near the Echinades Islands in western Greece, and divided ancient Acarnania and Aetolia.
[133] According to Strabo, some writers "conjecturing the truth from the myths" attributed various legends concerning the river-god, to features of the Achelous River itself.
[143] Ovid, in his Metamorphoses, provided a descriptive interlude when Theseus is the guest of Achelous, waiting for the river's raging flood to subside: "He entered the dark building, made of spongy pumice, and rough tuff.