Thyestes was a son of Pelops and Hippodamia. By him (and so incestuously) his daughter Pelopia bore Aegisthus (who killed Agamemnon). His name suggests anger, from thyo, 'to rage', 'storm', and we know that with his brother Atreus he killed their half-brother Chrysippus. An identical verb thyo, however, means 'to sacrifice', and this may refer to the many flocks and herds he was said to possess.