(Ἀχελῷος), the god of the river Achelous which was the greatest, and according to tradition, the most ancient among the rivers of Greece. He with 3000 brother-rivers is described as a son of Oceanus and Thetys (Hes. Th. 340), or of Oceanus and Gaea, or lastly of Helios and Gaea. (Natal. Com. 7.2.) The origin of the river Achelous is thus described by Servius (ad Virg. Georg. 1.9; Acn. 8.300): When Achelous on one occasion had lost his daughters, the Sirens, and in his grief invoked his mother Gaea, she received him to her bosom, and on the spot where she received him, she caused the river bearing his name to gush forth. Other accounts about the origin of the river and its name are given by Stephanus of Byzantium, Strabo (x. p.450), and Plutarch. (De Flum. 22.) Achelous the god was a competitor with Heracles in the suit for Deianeira, and fought with him for the bride. Achelous was conquered in the contest, but as he possessed the power of assuming various forms, he metamorphosed himself first into a serpent and then into a bull. But in this form too he was conquered by Heracles, and deprived of one of his horns, which however he recovered by giving up the horn of Amalthea. (Ov. Met. 9.8, &c.; Apollod. 1.8.1, 2.7.5.) Sophocles (Trachin. 9, &c.) makes Deianeira relate these occurrences in a somewhat different manner. According to Ovid (Ov. Met. 9.87), the Naiads changed the horn which Heracles took from Achelous into the horn of plenty. When Theseus returned home from the Calydonian chase he was invited and hospitably received by Achelous, who related to him in what manner he had created the islands called Echinades. (Ov. Met. 8.547, &c.) The numerous wives and descendants of Achelous are spoken of in separate articles. Strabo (x. p.458) proposes a very ingenious interpretation of the legends about Achelous, all of which according to him arose from the nature of the river itself. It resembled a bull's voice in the noise of the water; its windings and its reaches gave rise to the story about his forming himself into a serpent and about his horns; the formation of islands at the mouth of the river requires no explanation. His conquest by Heracles lastly refers to the embankments by which Heracles confined the river to its bed and thus gained large tracts of land for cultivation, which are expressed by the horn of plenty. (Compare Voss, Mytholog. Briefe, lxxii.) Others derive the legends about Achelous from Egypt, and describe him as a second Nilus. But however this may be, he was from the earliest times considered to be a great divinity throughout Greece (Hom. Il. 21.194), and was invoked in prayers, sacrifices, on taking oaths, &c. (Ephorus apud Macrob. 5.18), and the Dodonean Zeus usually added to each oracle he gave, the command to offer sacrifices to Achelous. (Ephorus, l.c.) This wide extent of the worship of Achelous also accounts for his being regarded as the representative of sweet water in general, that is, as the source of all nourishment. (Verg. G. 1.9, with the note of Voss.) The contest of Achelous with Heracles was represented on the throne of Amyclae (Paus. 3.18.9), and in the treasury of the Megarians at Olympia there was a statue of him made by Dontas of cedar-wood and gold. (Paus. 6.19.9.) On several coins of Acarnania the god is represented as a bull with the head of an old man. (Comp. Philostr. Imag. n. 4.)