Greek mythology, Iapetus (also  Japetus ( Ancient Greek: ? Iapetos)) was a  Titan, the son of Uranus and Gaia    and father of  Atlas, Prometheus, Epimetheus, and Menoetius. He was also called the father of Buphagus and  Anchiale in other sources.
Iapetus has been equated with
Japheth () the son of Noah as the progenitor of mankind based on the similarity of their names and the tradition. Iapetus was linked to Japheth by 17th-century theologian Matthew Poole, Robert Graves, and John Pairman Brown.  
Iapetus ("the Piercer") is the one
Titan mentioned by Homer in the as being in Iliad Tartarus with Cronus. He is a brother of Cronus, who ruled the world during the Golden Age. 
Iapetus' wife is usually described as a daughter of
Oceanus and Tethys named either Clymene (according to Hesiod and Hyginus) or  Asia (according to Pseudo-Apollodorus).
Hesiod's Prometheus is addressed as "son of Iapetus", and no mother is named. However, in Hesiod's Works and Days , Clymene is listed as Iapetus' wife and the mother of Prometheus. In Theogony Aeschylus's play Prometheus Bound, Prometheus is son of the goddess Themis with no father named (but still with at least Atlas as a brother). However, in Horace's Odes, in Ode 1.3 Horace writes "audax Iapeti genus ... Ignem fraude mala gentibus intulit" ("The bold offspring of Iapetus [i.e. Prometheus] ... brought fire to peoples by wicked deceit").
The sons of Iapetus were sometimes regarded 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's family tree 
Wells, John (14 April 2010). "Iapetus and tonotopy". John Wells's phonetic blog . Retrieved 2010.
^ Of uncertain etymology;
R. S. P. Beekes has suggested a pre-Greek origin ( Etymological Dictionary of Greek, Brill, 2009, pp. 573-4).
Hesiod, , Theogony 135.
Diodorus Siculus . Bibliotheca historica, 5.66.3
Clement of Alexandria . Recognitions, 31
Pseudo- Apollodorus. Bibliotheca, 1.1.3
Pausanias. Description of Greece, 8.27.17
Stephanus of Byzantium. Ethnica. s. v. Anchiale
^ Robert Graves,
The Greek Myths vol. 1 p. 146
^ John Pairman Brown,
Israel and Hellas (1995), 82
Homer. , Iliad 8.478-481
^ Smiley, Charles N. "Hesiod as an Ethical and Religious Teacher",
The Classical Journal, vol. XVII, 1922; pg. 514
Hesiod, Theogony 132-138, 337-411, 453-520, 901-906, 915-920; Caldwell, pp. 8-11, tables 11-14.
^ Although usually the daughter of Hyperion and Theia, as in
Hesiod, Theogony 371-374, in the (4), Homeric Hymn to Hermes 99-100, Selene is instead made the daughter of Pallas the son of Megamedes.
^ According to
Hesiod, Theogony 507-511, Clymene, one of the Oceanids, the daughters of Oceanus and Tethys, at Hesiod, Theogony 351, was the mother by Iapetus of Atlas, Menoetius, Prometheus, and Epimetheus, while according to Apollodorus, 1.2.3, another Oceanid, Asia was their mother by Iapetus.
^ According to
Plato, , Critias 113d-114a, Atlas was the son of Poseidon and the mortal Cleito.
Aeschylus, 18, 211, 873 (Sommerstein, pp. Prometheus Bound 444-445 n. 2, 446-447 n. 24, 538-539 n. 113) Prometheus is made to be the son of Themis.
Hesiod's Theogony, Focus Publishing/R. Pullins Company (June 1, 1987). ISBN 978-0-941051-00-2.
Clement of Alexandria, Recognitions from Ante-Nicene Library Volume 8 , translated by Smith, Rev. Thomas. T. & T. Clark, Edinburgh. 1867. Online version at theoi.com
Diodorus Siculus, The Library of History translated by Charles Henry Oldfather. Twelve volumes. Loeb Classical Library. Cambridge, Massachusetts: Harvard University Press; London: William Heinemann, Ltd. 1989. Vol. 3. Books 4.59–8. Online version at Bill Thayer's Web Site
Diodorus Siculus, Bibliotheca Historica. Vol 1-2. Immanel Bekker. Ludwig Dindorf. Friedrich Vogel. in aedibus B. G. Teubneri. Leipzig. 1888-1890. Greek text available at the Perseus Digital Library.
Hesiod, Theogony from The Homeric Hymns and Homerica with an English Translation by Hugh G. Evelyn-White, Cambridge, MA.,Harvard University Press; London, William Heinemann Ltd. 1914. Online version at the Perseus Digital Library. Greek text available from the same website.
Hesiod, Works and Days from The Homeric Hymns and Homerica with an English Translation by Hugh G. Evelyn-White, Cambridge, MA.,Harvard University Press; London, William Heinemann Ltd. 1914. Online version at the Perseus Digital Library. Greek text available from the same website.
Homer, with an English Translation by A.T. Murray, Ph.D. in two volumes. Cambridge, MA., Harvard University Press; London, William Heinemann, Ltd. 1924. The Iliad Online version at the Perseus Digital Library.
Homer. Homeri Opera in five volumes. Oxford, Oxford University Press. 1920. Greek text available at the Perseus Digital Library.
, in Homeric Hymn to Hermes (4) The Homeric Hymns and Homerica with an English Translation by Hugh G. Evelyn-White, Cambridge, Massachusetts., Harvard University Press; London, William Heinemann Ltd. 1914. Online version at the Perseus Digital Library.
Pausanias, Description of Greece with an English Translation by W.H.S. Jones, Litt.D., and H.A. Ormerod, M.A., in 4 Volumes. Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1918. Online version at the Perseus Digital Library
Pausanias, Graeciae Descriptio. 3 vols. Leipzig, Teubner. 1903. Greek text available at the Perseus Digital Library.
Pseudo-Apollodorus, The Library with an English Translation by Sir James George Frazer, F.B.A., F.R.S. in 2 Volumes, Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1921. Online version at the Perseus Digital Library. Greek text available from the same website. Stephanus of Byzantium, Stephani Byzantii Ethnicorum quae supersunt, edited by August Meineike (1790-1870), published 1849. A few entries from this important ancient handbook of place names have been translated by Brady Kiesling. Online version at the Topos Text Project.