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.
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.
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.
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.