After Herakles' ascension from earth to Olympos, his mortal rival King Eurystheus of Argos (who had devised his Labours) was afraid that Herakles' sons might grow up to contest the throne. He harried them from town to town across Greece, demanding that they be returned to Argos on pain of invasion. The play takes place after the children, led by Herakles' aged mother Alkmene and his equally decrepit nephew and former companion Iolaos, take refuge in Marathon, a town in Attika not far from Athens. The Argives then declare war on Marathon and the Athenians, a war whose victory is underwritten for the Athenians by the decision of Herakles' daughter Makaria, to allow herself to be sacrificed to the gods. The subsequent defeat of the Argives, and the punishment of Eurystheus, defines the second half of the play, which was first produced some time between 430 and 427 BC.