His genealogy was traced through Aristodemus, Aristomachus, Cleodaeus and Hyllus to Heracles (Herodotus vii.
Services rendered to Aegimius by Heracles led (I) to the adoption of Hyllus, son of Heracles, by Aegimius, side by side with his own sons Dymas and Pamphylus, and to a threefold grouping of the Dorian clans, as Hylleis, Dymanes and Pamphyli; (2) to the association of the people of Aegimius in the repeated attempts of Hyllus and his family to recover their lost inheritance in VIII.
In the 5th century Pindar ascribes to Aegimius the institutions of the Peloponnesian Dorians, and describes them as the " Dorian folk of Hyllus and Aegimius," and as " originating from Pindus " (Pyth.
From Trachis he wages successful war against the Dryopes and Lapithae as ally of Aegimius, king of the Dorians, who promised him a third of his realm, and after his death adopted Hyllus, his son by Deianeira.
HERACLIDAE, the general name for the numerous descendants of Heracles (Hercules), and specially applied in a narrower sense to the descendants of Hyllus, the eldest of his four sons by Deianeirathe, conquerors of Peloponnesus.
Hyllus and his brothers then invaded Peloponnesus, but after a year's stay were forced by a pestilence to quit.
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.
After the death of Aegimius, his two sons, Pamphilus and Dymas, voluntarily submitted to Hyllus (who was, according to the Dorian tradition in Herodotus v.
Being desirous of reconquering his paternal inheritance, Hyllus consulted the Delphic oracle, which told him to wait for "the third fruit," 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.