Eurystheus was a grandson of Perseus and Andromeda. Eurystheus' father was Sthenelos. This makes
Hercules a cousin of Eurystheus. Since Eurystheus was born before Hercules, he became king of Mycenae and Tiryns. In the story
of Hercules told by Apollodorus, Hercules serves Eurystheus for 12 years as penance for killing his own children. Eurystheus
set before Hercules seemingly impossible tasks that the king did not profit from. Eurystheus seemed to be afraid of Hercules,
but survived the hero and after his death feared the retribution of the children of Hercules.