Somnus: The Personification of Sleep

Somnus is one of the more obscure deities in Greco-Roman mythology. Somnus or Hypnos (as was his Greek name) is the shadowy Roman god of sleep.

Indeed, he was considered the personification of sleep by the ancient Greeks and Romans. As is rather fitting of the god of sleep, Somnus seems to be a mysterious figure existing on the edges of the myths and stories of the time. His position either as a figure of good or evil seems quite unclear.

Who Was Somnus?

Somnus was the Roman god of sleep. Not much is known about him, other than his interesting family ties and place of residence. The Roman equivalent of the Greek Hypnos, the gods of sleep in the Greco-Roman tradition are not as flashy and conspicuous as some of the other gods. They had the ability to induce sleep in mortals as well as other gods.

According to modern sensibilities, we might be a little wary of Somnus, the brother of Death with his house in the underworld. But he does not seem to have been an ominous figure for the Romans, as they believed a person should pray to him for a restful night of sleep.

READ MORE: 10 Gods of Death and the Underworld From Around the World

What Exactly Does It Mean to Be a God of Sleep?

While there are several gods and goddesses in various ancient cultures who are associated with the night, the moon, and even dreams, the idea of a specific deity connected to sleep seems to have been unique to the Greeks and, by extension, the Romans who borrowed the concept from them.

As the personification of sleep, Somnus’ duty appears to have been to influence mortals and gods alike to fall asleep, at times at the command of another god. Ovid speaks of him as one who brings rest and prepares the body for the work and labor of the following day. In the myths in which he appears, his natural ally seems to be Queen Hera or Juno, whether that be to trick Zeus or Jupiter or to send Alcyone dreams while she is asleep.

Other Deities Connected with Sleep and Night

Interestingly enough, most ancient cultures had a goddess of the night. Some examples were the Egyptian goddess Nut, the Hindu goddess Ratri, the Norse goddess Nott, the primordial Greek goddess Nyx, and her Roman equivalent Nox. Somnus’ father Scotus, the Roman counterpart of the Greek Erebus, was the primordial god of darkness, making him a good match for Nox. There were even guardian deities who protected people during the night and gave them dreams, such as the Lithuanian goddess Breksta.

But Somnus was the only god who was so clearly and solely associated with the act of sleeping.

Etymology and Meaning of the Name Somnus

The Latin word ‘somnus’ means ‘sleep’ or drowsiness.’ Even now, this word is familiar to us through the English words ‘somnolence’ which is a strong desire for sleep or a general feeling of drowsiness, and ‘insomnia’ which means ‘sleeplessness.’ Insomnia is one of the most common sleeping disorders in the world today. Insomnia makes it hard for the person to fall asleep or stay asleep for long.

It is possible that the name could be derived from the Proto-Indo-European root ‘swep-no’ which means ‘to sleep.’

Hypnos: The Greek Counterpart of Somnus

It is not possible to know the exact origins of Somnus as a Roman god. But it is clear that there was a lot of influence from Greek mythology when it came to him. Did he exist as a deity outside of the Greek influence? It cannot be said for sure. However, given his parentage and the stories surrounding him, the connection to Hypnos is impossible to miss.

Hypnos, the Greek god of and personification of sleep, was the son of Nyx and Erebus who lived in the underworld with his brother Thanatos. The most significant appearance that Hypnos makes in Greek myth is in connection with the Trojan War in The Iliad by Homer. In conjunction with Hera, he is the one who puts Zeus, the champion of the Trojans, to sleep. Therefore, the success of the Greeks against the Trojans can be attributed in part to Hypnos.

Once Zeus is asleep, Hypnos travels to Poseidon to tell him that he can help the Greeks on their course since Zeus can no longer act to stop them. While Hypnos does not seem an altogether willing participant in this scheme, he does agree to ally with Hera once she promises that he can marry Pasithea, one of the younger Graces, in exchange for his help.

At any rate, it seems that both Hypnos and Somnus had to be nudged into action and were not much inclined to take part in the politics between the Greek gods willingly.

The Family of Somnus

The names of Somnus’ family members are far more well-known and famous as compared to the elusive god of sleep. As the son of Nox and Scotus, both extremely powerful primordial deities, there is no doubt that Somnus too must have had immense power.

The Son of Night

Somnus was the son of the goddess of and personification of the night itself, Nox. According to some sources, Scotus, the god of darkness and one of the original deities predating even the Titans, is considered his father. However, some sources, such as Hesiod, do not specify his father at all and imply that he was one of the children Nox brought forth on her own.

It is fitting indeed that the goddess of the night should give birth to the god of sleep. An equally shadowy figure as her son, there is very little about Nox that is known other than that she was said to be one of the first deities born out of chaos. Predating the Olympian Gods by far, it is perhaps little wonder that there is so little information about these older beings who seem less like gods and more like powerful, immovable forces of the universe.

Brother of Death

According to Virgil, Somnus was the brother of Mors, the personification of death, and also a son of Nox. The Greek equivalent of Mors was Thanatos. While the name Mors is feminine, ancient Roman art still depicted Death as a man. This is a striking contrast to written accounts, where poets were bound by the gender of the noun to make Death a woman.

Sons of Somnus

The Roman poet Ovid’s account mentions Somnus having a thousand sons, called Somnia. The word means ‘dream shapes’ and the Somnia appeared in many forms and were believed to be able to change forms. Ovid names only three of Somnus’ sons.


Morpheus (meaning ‘form’) was the son who would appear in the dreams of mankind in human form. According to Ovid, he was particularly skilled at mimicking the stature, gait, and habits of mankind. He had wings on his back, like all beings that were connected to sleep in any manner. He has lent his name to the character Morpheus from The Matrix films and was the influence behind the main character of Neil Gaiman’s The Sandman, Morpheus or Dream.


Icelos (meaning ‘like’) or Phobetor (meaning ‘frightener’) was the son who would appear in a person’s dreams in the guise of an animal or beast. Ovid said that he could appear in the form of a beast, a bird, or a long serpent. It is not clear why the serpent is being differentiated from beasts over here, but at any rate, this son was adept at mimicking the guises of animals.


Phantasos (meaning ‘fantasy’) was the son who could take on the appearance of inanimate objects in dreams. He would appear in the shape of earth or trees, rocks or water.

READ MORE: Who Invented Water? History of the Water Molecule

Phantasos, like his brothers Morpheus and Icelos/Phobetor, does not appear in any other works than Ovid’s. This may mean that the names are Ovid’s inventions but it is also equally possible that the poet was drawing on older oral tales in the naming and personalities of these three.

Somnus and Dreams

Somnus did not himself bring dreams but he had a connection to dreaming through his sons, the Somnia. The word ‘somnia’ means ‘dream shapes’. A thousand sons of Somnus brought many varieties of dreams to people in their sleep. In fact, as the tale of Ceyx and Alcyone in Ovid’s Metamorphoses demonstrates, sometimes one had to approach Somnus first to entreat his sons to carry dreams to the human in question.

Somnus and the Underworld

Just like in the Greek tales by Hesiod, in the Roman tradition Sleep and Death both live in the Underworld. Homer’s account had the land of dreams, the home of Hypnos or Somnus, located on the road to the underworld, near the river Oceanus of the Titan Oceanus.

Unlike the Christian hell, the Greco-Roman underworld is not a place of doom and gloom but a place that all beings go to after death, even the heroic ones. Somnus’ association with it does not make him an ominous or frightening figure.

Somnus in Ancient Roman Literature

Somnus is mentioned in the works of two of the greatest Roman poets of all time, Virgil and Ovid. What little we know of the Roman god of sleep comes from these two poets.


Virgil, like Homer and Hesiod before him, also has Sleep and Death as brothers, with their houses at the entrance to the underworld, just next to each other.

Virgil also has Somnus make a small appearance in The Aeneid. Somnus disguises himself as a shipmate and goes to Palinarus, the helmsman in charge of steering Aeneas’ ship and staying on course. First, he offers to take over so Palinarus can get a good night’s rest. When the latter refuses, Somnus causes him to slumber and pushes him off the boat while asleep. He uses the water of Lethe, the river of forgetfulness in the underworld, to send him to sleep.

The death of Palinarus is the sacrifice demanded by Jupiter and the other gods for granting Aeneas’ fleet safe passage to Italy. This time, Somnus seems to be working on behalf of Jupiter.


Somnus and his sons appear in Ovid’s Metamorphoses. Ovid gives an elaborate account of Somnus’ home. In Book 11, there is also a tale of how Juno’s attendant Iris makes her way to Somnus’ home on a mission.

The House of Somnus

The house of Somnus is not a house at all but a cave, according to Ovid. In that cave, the sun can never show its face and you can hear no cock crow and no dog bark. In fact, even the rustling of branches cannot be heard inside. There are no doors so that no hinges can creak. In this abode of peace and restful silence, dwells Sleep.

Ovid also mentions that the Lethe flows through the bottom of Somnus’ cave and its gentle murmur adds to the aura of sleepiness. Near the entrance of the cave, there bloom poppies and other drugging plants.

In the center of the cave is a soft black couch on which sleeps Somnus, surrounded by his many sons, who bring dreams in many forms to all beings.

Somnus and Iris

Book 11 of Metamorphosis tells the tale of Ceyx and Alcyone. In this, Somnus plays a small part. When Ceyx dies at sea during a violent storm, Juno sends her messenger and attendant Iris to Somnus to ask him to send a dream to Alcyone disguised as Ceyx. Iris arrives at the cave and carefully navigates her course through the sleeping somnia in her way.

Her clothes shine brightly and wake Somnus. Iris gives him Juno’s command and swiftly leaves his cave, out of anxiety that she too shall succumb to sleep. Somnus wakes his son Morpheus to carry out Juno’s orders and immediately returns to his nap on his soft couch.

Somnus in the Percy Jackson Series

Somnus appears briefly in the famous Percy Jackson series by Rick Riordan. Clovis is mentioned to be his demigod child in Camp Half-Blood. He is said to be a very strict and warlike disciplinarian and will even kill someone for sleeping at their post.

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