In Greek mythology, Aepytus (Ancient Greek: Αἴπυτος, Aípytos) was the youngest son of Cresphontes the Heraclid, king of Messenia, and of Merope, daughter of the Arcadian king Cypselus. When his father and brothers were murdered in an insurrection, Aepytus alone survived because he was being raised in the house of his maternal grandfather Cypselus. On reaching manhood he returned to Messenia, punished his father's murderers, and put to death the usurper Polyphontes, recovering the throne of his ancestors. From him the later kings of Messenia were called Aepytids rather than the more general name Heraclids.
Adapted from Wikipedia, "Aepytus (son of Cresphontes)" · CC BY-SA 4.0
I.Family
Aepytus was the youngest son of Cresphontes the Heraclid, king of Messenia, and of Merope, the daughter of the Arcadian king Cypselus. His father and his other brothers were killed in the insurrection that overthrew the household, leaving Aepytus as the sole survivor of his immediate family.
Through his maternal line he was connected to the royal house of Arcadia, having been raised in the house of his grandfather Cypselus. Aepytus himself became the father of Glaucus, who continued the Messenian royal line he had restored.
II.Mythology
Cresphontes and his other sons were murdered during an insurrection. Aepytus alone escaped the danger, because he was being educated in the house of his grandfather Cypselus. In the meantime the throne of Cresphontes was occupied by the Heraclid Polyphontes, who also forced Merope to become his wife.
When Aepytus reached manhood he was enabled, by the aid of his uncle Holaeas, to return to his kingdom of Messenia. There he punished the murderers of his father and put Polyphontes to death, recovering the throne that had belonged to his ancestors.
III.Legacy and the Aepytid line
After Aepytus recovered the Messenian kingdom, the subsequent kings of Messenia were called Aepytids, taking their name from him, instead of bearing the more general name Heraclids shared by the wider descendants of Heracles.
The story of Aepytus is preserved in the ancient sources, with citations drawn from Apollodorus (Bibliotheca 2.8.5), Pausanias (Description of Greece, including 4.3.3 and 8.5.6–7), and Hyginus (Fabulae 137).