Yggdrasil: The World Tree in Norse Mythology

Yggdrasil, the Norse world tree or cosmic tree sits at the center of the universe in Norse mythology. The nine realms of the Norse cosmos are tucked into the roots and branches of the sacred tree, and Yggdrasil connects the worlds and also separates them, maintaining the cosmic order.

The Backbone of the Norse Universe

In Norse cosmology, Yggdrasil is described as an enormous every-green ash tree that cradles the nine worlds of the Norse universe and nourishes all things. It is seen as a living, breathing entity.

Exactly which nine worlds make up the Norse universe is unclear. While we are told that there are nine, we are never given a definitive list, and the accepted list is derived from a variety of sometimes conflicting sources for Norse mythology.

The name Yggdrasil probably means “horse of Odin” in Old Norse, which can also be interpreted as “gallows of Odin”. Yggr means terror, and was one of the names given to Odin, while drasil means horse. This may be a reference to the story that Odin hung himself from Yggdrasil, while pierced by his own spear, for nine days and nine nights to learn the secrets of the runes.

The Nine Realms

Norse cosmology consistently states that there are nine realms in the Norse universe, but it is not exactly clear what those nine realms are. Some are certain, and some are open to interpretation.

Asgard is the realm of the Aesir gods ruled over by Odin. This is also where Valhalla, the afterlife of warriors, is located. It is often described as being among the upper branches of the world tree.

Jotunheim is the realm of the giants, jotuns, who are mortal enemies of the Aesir. They are considered a force of chaos in the universe. Despite enmity with the Aesir, interbreeding between gods and jotun was very common and they seemed to be different tribes, but the same type of supernatural entities.

Midgard is said to be located at the center of the world tree and is the realm of men. It is surrounded by a huge ocean that makes it inaccessible from the other realms, except Asgard, which is linked with Midgard by the rainbow Bifrost bridge.

Nilfheim is the realm of ice and mist inhabited by ice giants. Along with Muspelheim, it is the oldest of the Norse realms and is located among the roots of the world tree.

Muspelheim – the primordial world of fire and home to the fire giants ruled by Sutr, a mortal enemy of Odin. Sutr will lead the charge against Asgard during Ragnarok.

Vanaheim is the home of the Vanir gods, another race similar to the Aesir and the jotun. But while the Aesir were gods of society and law, the Vanir were nature deities, and gods of magic and sorcery.

Alfheim is home to the light elves, beautiful creatures that shine more brightly than the son and may have been similar to angels. They are sometimes conflated with the blessed ancestors.

Svartalfheim is the home of the dark elves, more commonly known as dwarves, who prefer to live underground. Great artisans and blacksmiths, they made most of the treasures mentioned in the Norse stories, including Thor’shammer Mjolnir.

The ninth and final realm is unclear. It could be Helheim, the realm of the dead ruled over by the giantess Hel. But the underworld Helheim is also described as a stronghold located within Niflheim. Another possibility is a realm called Nidavellir, which means dark fields and is thought to be home to the dwarves, so this could just be another name for Svartalfheim. The ninth realm could be an unknown realm not mentioned in the surviving sources.

The Three Wells

Yggdrasil is fed by three wells located in three of the Norse realms. The first, Urdarbrunnr, the Well of Destiny, is located in Asgard and is also the dwelling place of the Norns, the Norse Fates. They are variously described as writing destiny using the runes and spinning the destinies of individuals of a spindle.

The second well, Mimisbrunnr, the Well of Wisdom, was located in Niflheim, one of the realms at the very bottom of Yggdrasil. The root that it is connected to passes through Jotunheim, which seems to be close to Midgard as they are separated by a forest called the Ironwood and the sea that surrounds Midgard. When the wise advisor Mimir died, Odin placed his head at the Well of Wisdom and magically reanimated it so that he would not lose his wise counselor.

Mimameidr may have been an alternative name for Yggdrasil, which means Mimir’s tree. This may be a reference to the fact that Yggdrasil was fed by the Mimmisbrunnr. The tree is also occasionally called Hoddmimis Holt, which means Mimir’s forest.

The third well, Hvergelmir, the burning hot well, is also located in Niflheim. This well feeds eleven rivers that flow through the Norse realms. The dragon Nidhogg lives here and gnaws on the roots of Yggdrasil. The stag Eikthyrnir also lives here. He feeds on Yggdrasil, causing water to spout from his horns and replenish the well.

The Animals of Yggdrasil

Several animals live within Yggdrasil, rather than one of its realms. A mighty eagle that knows many things lives at the very top of Yggdrasil. We are not given the name of the eagle, but he must be enormous as a hawk called Vedrfolnir sits between his eyes. This name means “storm pale” or “wind bleached”, which may suggest harsh conditions at the very top outside the protection of Yggdrasil.

At the very bottom of Yggdrasil among the roots of the tree lives a dragon or a snake called Nidhoggr. The Vikings did not differentiate between dragons and serpents. The name Nidhoggr means curse striker or malice striker. Nidhoggr is an angry and mean creature who is stuck in a feud with the eagle at the top of the tree.

However, neither the eagle nor Nidhoggr seems to be able to leave their homes to pursue their mutual dislike. But a squirrel called Ratatoskr runs freely up and down the full height of the tree. His main pastime is to carry messages between the feuding eagle and dragon. He is also said to share gossip and add fuel to the fire to feed the conflict. The name Ratatoskr means “drill tooth” or “bore tooth”, and he also nourishes himself by chewing on the bark of Yggdrasil.

He is joined in this pastime by four harts or stags that munch on the branches of the tree. But in return for this nourishment, morning dew forms on the horns of the stags and creates rivers that nourish the realms. Nevertheless, the names of the stags suggest that they are not “friends” of the tree. They are called Dainn, “dead one”, Dvalinn, “unconscious one”, “Duneyrr, “thundering in the ear”, and Durathror, “thriving slumber”.

It is probably because Yggdrasil is constantly eaten away at that the tree is described as being in more pain than a man could imagine. This eating away also suggests that Yggdrasil is mortal and has a finite lifespan.

Nidhoggr is described as living among the roots of Yggdrasil, but he does not live there alone. He is part of a colony of serpents, and he may be their leader. According to the Poetic Edda, the roots of which Nidhoggr chews are located in the icy world of Niflheim alongside one of the three wells that feed Hvergelmir. The dragon is constantly gnawing, perhaps in an effort to free himself and climb the tree as the roots are holding him prisoner. But he will stop gnawing when he hears the howl of Garm, the guard dog of Helheim. The dog howls when new dead souls are brought to Helheim, and this summons the dragon to its gates. There, the worst of the worst, murders and oath breakers, are sent to an area of Helheim called Nastrond. There, Nidhoggr sucks on the blood of the dishonorable deceased.

Yggdrasil at Ragnarok

Ragnarok is a prophecy that predicts the death of the Norse gods and the destruction of the world. According to the Ragnarok prophecy, a rooster will warn Odin that the end of the world is nigh. Odin will then travel to Mimisbrunnr to consult Mimir.

Meanwhile, the coming of Ragnarok is heralded in the world of men by a series of disasters including famine and war. Eventually, there will be violent earthquakes in Midgard, caused by shockwaves that travel the length of Yggdrasil. These same shockwaves will crack open the world of Muspelheim, allowing the fire giants trapped there to move into other realms. The earthquakes will also shake free the ship Naglfar, which is made from the fingernails and toenails of the dead, which Loki will use to sail to Asgard with his allies to battle the Aesir gods.

While the destruction of the nine worlds of Norse mythology is described, the specific fate of Yggdrasil itself is not detailed in the Ragnarok prophecy. Some sources suggest that all that exists sinks back into the waters of chaos from which they came. Others suggest that a new world emerged from the waters and that the survivors started over. But this seems to be a later Christian addition to the story, referencing both the flood myth and the idea of the meek inheriting the earth after the second coming of Christ.