In Greek mythology, dreams were sometimes personified as Oneiros or Oneiroi. In the Iliad of Homer, Zeus sends an Oneiros to appear to Agamemnon in a dream, while in Hesiod's Theogony, the Oneiroi are the sons of Nyx (Night), and brothers of Hypnos (Sleep).
"Nestor Appearing in a Dream to Agamemnon" (1805) by Henry Fuseli
The Theogony is a poem by Hesiod describing the origins and genealogies of the Greek gods, composed c. 730–700 BC. It is written in the Epic dialect of Ancient Greek and contains 1022 lines. It is one of the most important sources for the understanding of early Greek cosmology.
Fourteenth-century Greek manuscript of Hesiod's Theogony with scholia written in the margins
The nine muses on a Roman sarcophagus (second century AD)—Louvre, Paris
The Mutilation of Uranus by Saturn: fresco by Giorgio Vasari and Cristofano Gherardi, c. 1560(Sala di Cosimo I, Palazzo Vecchio)
The Fall of the Titans by Cornelis Cornelisz van Haarlem (1596–1598)