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Achelous, a MythSource painting
Greek

Achelous

Lord of Rivers · Silver-Swirling · Father of Rivers

01Identity

Achelous in Greek tradition

As a river deity, Achelous fought Heracles for Deianeira, taking serpent and bull forms before Heracles broke off one of his horns. He conceded defeat, and Heracles won Deianeira as his bride. In the related account, Achelous exchanged the broken horn for Amalthea’s horn, which became the cornucopia, linking the Lord of Rivers with fertility and abundance.

Top questions

The quick answers

  • Who is Achelous?

    Achelous is a Greek deity associated with rivers and freshwater; springs and streams; fertility; and abundance and agricultural prosperity.
    Source

    Source

    • Classical Mythology a to Z

  • What is Achelous the god of?

    Achelous is associated with rivers and freshwater; springs and streams; fertility; and abundance and agricultural prosperity.
    Source

    Source

    • Classical Mythology a to Z

  • What family links are recorded for Achelous?

    Mother: Nais, Spouse: Calliope, 14 children.
02Family

Achelous’s family, at a glance

Nais
Achelous

with Calliope, Melpomene, Perimede, Sterope, Terpsichore

AcheloidesAglaopeAglaophónosCallirhoeCastaliaErysicheHippodamasLeucosia
LigeiaMolpeParthenopePirenePisinoëThelxiepea
03The names

The names Achelous answers to

Acheloos

Modern transliteration of the Greek name

SourceClassical Mythology a to Z

Akheloios

Scholarly transliteration of the Greek name

SourceClassical Mythology a to Z

Father of Rivers

Poetic title emphasizing his river-god status

SourceClassical Mythology a to Z

Lord of Rivers

Title for his authority over rivers

SourceClassical Mythology a to Z

04The myths

The myths of Achelous

2 myths, with sources recorded for each.

Achelous Battles Heracles for Deianeira

Achelous faced Heracles in single combat for the right to marry Deianeira, daughter of Oeneus, king of Aetolia. Both had claimed her hand, so the matter was to be settled by fighting. Achelous, the river god, trusted his ability to change his shape during the contest.

He first assumed the form of a serpent. Heracles continued to fight him and did not yield to the change. Achelous then took the form of a bull. Heracles seized the advantage in that shape, overpowered him, and broke off one of his horns. Achelous was forced to admit defeat and withdrew from the contest.

Heracles therefore won Deianeira as his wife. The account also identifies Achelous as a river, described as the largest in Greece. It flowed along the Acarnanian frontier of Aetolia for part of its course. River gods were thought to appear in the form of bulls. This belief accounts for Achelous’s final shape during the combat. His changes of form allowed him to challenge Heracles in different ways, but they did not prevent Heracles from overcoming him. After the horn was broken and the contest ended, Achelous gave up his claim to Deianeira, leaving Heracles as the victor and her future husband.

Achelous Battles Heracles for Deianeira, a MythSource painting of the scene

3 sources· checked 2026-08-19

  1. 1Greek Myths & TalesT1
  2. 2Apollodorus, The LibraryT1

    Quote

    “Achelous fought Heracles for Deianeira, changing into a serpent and then a bull, until Heracles broke off the bull’s horn and won the contest.”

    Apollodorus, The Library

  3. 3The Library of Greek Mythology (Oxford World's Classics)T1

Achelous Gives Up the Horn of Plenty

Heracles arrived in Calydon and sought Deianeira, the daughter of Oineus, king of Aetolia. Achelous, the river god, also wanted to marry her. They agreed that Deianeira’s hand would go to the victor in single combat. Achelous trusted his power to assume different forms, but this did not secure his victory.

Achelous changed into a bull. Heracles seized him and broke off one of his horns. Achelous admitted defeat, and Heracles won Deianeira. The broken horn was exchanged for the horn of Amalthea. In another telling, the broken horn was first replaced and was then exchanged for Amalthea’s horn. The exchanged horn became the cornucopia, or horn of plenty.

In one telling, Amalthea was the nymph who fed the infant Zeus with milk from her goat, rather than the goat itself. In another, Zeus turned the goat into a constellation as a reward and gave one of its horns to the nymphs who had cared for him. He endowed the horn with the power to produce whatever they wished. On that telling, Amalthea’s horn was not a bull’s horn. Another telling identified it with the horn that Heracles broke from Achelous.

Achelous Gives Up the Horn of Plenty, a MythSource painting of the scene

2 sources· checked 2026-08-19

  1. 1The Library of Greek Mythology (Oxford World's Classics)T1
  2. 2Apollodorus, The LibraryT1

    Quote

    “When Heracles had broken off Achelous’s horn, Achelous gave him the horn of Amalthea, which could provide whatever its possessor desired.”

    Apollodorus, The Library

Also mentioned in

Stories elsewhere on MythSource that mention Achelous, each on that figure’s page.