Heracleidae

These Heraclids were a group of Dorian kings who conquered the Peloponnesian kingdoms of Mycenae, Sparta and Argos; according to the literary tradition in Greek mythology, they claimed a right to rule through their ancestor.

They withdrew to Thessaly, where Aegimius, the mythical ancestor of the Dorians, whom Heracles had assisted in war against the Lapithae, adopted Hyllus and made over to him a third part of his territory.

Desiring to reconquer his paternal inheritance, Hyllus consulted the Delphic oracle, which told him to wait for "the third fruit", (or "the third crop") and then enter Peloponnesus by "a narrow passage by sea".

Accordingly, after three years, Hyllus marched across the isthmus of Corinth to attack Atreus, the successor of Eurystheus, but was slain in single combat by Echemus, king of Tegea.

[3] The oracle, being again consulted by Temenus, bade him offer an expiatory sacrifice and banish the murderer for ten years, and look out for a man with three eyes to act as guide.

The Dorians followed the custom of other Greek tribes in claiming as ancestor for their ruling families one of the legendary heroes, but the traditions must not on that account be regarded as entirely mythical.

They represent a joint invasion of Peloponnesus by Aetolians and Dorians, the latter having been driven southward from their original northern home under pressure from the Thessalians.

That is about the time the Hurri-Hittite empire collapsed and thus the land of seha river could become independent from its Hittite overlords and gives more credibility to the tradition heard by Herodotus.

Their most celebrated members were Philip II of Macedon and his son Alexander the Great, under whose leadership the kingdom of Macedonia gradually gained predominance throughout Greece, defeated the Achaemenid Empire and expanded as far as Egypt and India.

[8][9] The Greek tragedians amplified the story, probably drawing inspiration from local legends which glorified the services rendered by Athens to the rulers of Peloponnesus.

A. Spranger found the political subtext of Heracleidae, never far to seek, so particularly apt in Athens towards the end of the peace of Nicias, in 419 BCE, that he suggested the date as that of the play's first performance.

As Eurystheus prepares to attack, an oracle tells Demophon that only the sacrifice of a noble woman to Persephone can guarantee an Athenian victory.