Eurystheus

Zeus announced before the assembled gods that the child about to be born to the house of Perseus would rule over its whole line. He meant Heracles, the son of Zeus and Alcmene, who was descended from Perseus through his mother. Hera understood this and, jealous of Zeus’s child by another woman, persuaded the Eileithuiai to delay Alcmene’s delivery.

Hera then arranged for Eurystheus to be born before Heracles. Eurystheus was the son of Sthenelos, and therefore another grandson of Perseus. He was born at seven months, while the birth of Heracles was held back. Since Zeus’s declaration could not be revoked, Eurystheus gained the kingship intended for Heracles and ruled in Mycenae. Heracles thereby became subject to his cousin and served him.

Heracles was born to Alcmene after Zeus had visited her in the likeness of Amphitryon. Zeus had prolonged that night to three times its usual length. When Amphitryon returned, Alcmene told him that he had already come the previous night, and Teiresias revealed that Zeus had slept with her. Alcmene later gave birth to two sons, Heracles, the son of Zeus, and Iphicles, the son of Amphitryon. Heracles was elder by a night.

Eurystheus’s position was later made clear when Heracles won fame through his victory over Erginus. Eurystheus, by then king of Mycenae, grew jealous of the young hero’s reputation and asserted his rights over him. The oath and declaration of Zeus had therefore placed Heracles beneath Eurystheus, despite Heracles being the child whom Zeus had intended to make ruler.

Eurystheus persecuted the sons of Heracles after their father had been taken to the gods. The Heraclids fled to King Ceyx at Trachin, accompanied by the aged Iolaus, their father’s nephew and lifelong companion. Iolaus guided and protected them. Eurystheus demanded that Ceyx surrender the fugitives and threatened war. Ceyx had too few forces to defend them against the powerful king of Argos, so the Heraclids left Trachin and fled through Greece. Eurystheus pursued them to Athens, where King Demophon, son of Theseus, received them and took up their cause.

Demophon prepared the Athenians to resist the force that Eurystheus had sent against them. An oracle then declared that victory required the sacrifice of a maiden of noble birth. The battle followed, with Hyllus, Iolaus, and the other Heraclids fighting beside the Athenians.

During the battle, Iolaus suddenly borrowed Hyllus’s chariot. He prayed to Zeus and Hebe to restore the strength and vigour of his youth for that one day. His prayer was granted. A thick cloud descended from heaven and covered the chariot. When the cloud disappeared, Iolaus stood there with the full strength of a young man. He led his warriors into the attack, and Eurystheus’s army broke and fled. Eurystheus was captured, and Demophon ordered his death.

Hyllus, Iolaus, and the other Heraclids gratefully acknowledged the Athenians’ help. They then left Athens and invaded the Peloponnese, which they regarded as the lawful inheritance of Heracles. Zeus had intended the land to belong to Heracles, so the Heraclids claimed it as their father’s rightful possession.