One morning Jupiter boasted among the gods in Olympus that a son would that day be born in the line of Perseus, who would rule over all the Argives.  Juno was angry and jealous at this, and, as she was the goddess who presided over the births of children, she contrived to hinder the birth of the child he intended till that day was over, and to hasten that of another grandson of the great Perseus.  This child was named Eurystheus, and, as he had been born on the right day, Jupiter was forced to let him be king of Argos, Sparta, and Mycenæ, and all the Dorian race; while the boy whom he had meant to be the chief was kept in subjection, in spite of having wonderful gifts of courage and strength, and a kind, generous nature, that always was ready to help the weak and sorrowful.