Image: Detail of Morpheus in Morpheus Awakening as Iris Draws Near by René-Antoine Houasse (1690)
In Greek mythology, the Oneiroi (“dreams”) are three gods or daimones of dreams. They are called the Somnia in Roman mythology.
According to Hesiod’s Theogony, they are sons of Nyx (no father), and are therefore brothers of Hypnos, Thanatos, the Moirai, the Hesperides, and the other offspring Nyx conceived and birthed by herself.
In Ovid’s Metamorphoses (be aware that this is a Roman source, not Greek), the Oneiroi are supposedly some of Hypnos’ thousand sons, and Ovid mentions them by name: Morpheus, Phantasos, and Phobetor (or Ikelos). The latter, Ovid states, mortals call Phobetor while gods call him Ikelos.
Morpheus is thought (by some) to be the leader of the Oneiroi. His name comes from the Greek word morphê (meaning “form” or “shape”). He shapes dreams, and has the ability to take human form and appear in dreams.
The name Phantasos comes from the word phantasioô (“bring images to the mind”).
Ikelos translates to “like” or “resembling”, and Phobetor stems from the word phobêtos (meaning “to be feared”).
In Homer’s Odyssey, the gates dreams travel through are described as two in number - one gate is fashioned of ivory, the other of horn. False or meaningless dreams are said to pass through the gate of ivory, while truthful, prophetic dreams wings their way out through the gate of horn.
Excerpt from book 19 of Homer’s Odyssey (trans. Shewring). Penelope to the disguised Odysseus:
"‘Dear guest, Oneiroi (Dreams) are beyond our unravelling - who can be sure what tale they tell? Not all that men look for comes to pass. Two gates there are that give passage to fleeting Oneiroi (Dreams); one is made of horn, one of ivory. The Oneiroi that pass through sawn ivory are deceitful, bearing a message that will not be fulfilled; those that come out through polished horn have truth behind them, to be accomplished for men who see them. But I cannot hope that this Oneiros (Dream) that bewilders me came from there.’"