He is a brother of Cronus, who ruled the world during the Golden Age but is now locked up in Tartarus along with Iapetus, where neither breeze nor light of the sun reaches them.
[8] Iapetus' wife is usually described as a daughter of Oceanus and Tethys named either Clymene (according to Hesiod[9] and Hyginus) or Asia (according to Apollodorus).
Hesiod and other Greek scholars regarded the sons of Iapetus as mankind's ancestors and as such, some of humanity's worst qualities were said to have been inherited from these four gods, each of whom were described with a particular moral fault that often led to their own downfall.
For instance, sly and clever Prometheus could perhaps represent crafty scheming; the inept and guileless Epimetheus, foolish stupidity; the enduring, strongest and powerful Atlas, excessive daring; and the arrogant Menoetius, rash violence.
Iapetus was linked to Japheth by 17th-century theologian Matthew Poole[11] (and more recently by Robert Graves)[12] and by John Pairman Brown.