Yggdrasil (Old Norse Yggdrasill or Askr Yggdrasils) is the mighty tree whose trunk rises at the geographical center of the Norse spiritual cosmos. The rest of that cosmos, including the Nine Worlds, is arrayed around it and held together by its branches and roots, which connect the various parts of the cosmos to one another. Because of this, the well-being of the cosmos depends on the well-being of Yggdrasil. When the tree trembles, it signals the arrival of Ragnarok, the destruction of the universe.[1]

The first element in Yggdrasil’s name, Yggr (“Terrible”), is one of the countless names of the god Odin, and indicates how powerful and fearsome the Vikings perceived him to be. The second element, drasill, means “horse.” So Yggdrasil’s name means “Horse of Odin,” a reference to the time when the Terrible One sacrificed himself to discover the runes. The tree was his gallows and bore his limp body, which the Norse poetic imagination described metaphorically as a horse and a rider.[2]

In Old Norse literature, Yggdrasil is commonly said to be an ash tree,[3] but at other times, it’s said that no one knows the species to which the magnificent tree belongs.[4] As with so many aspects of Norse mythology and religion, there doesn’t seem to have been any airtight consensus on this during the Viking Age.

In the words of the Old Norse poem Völuspá, Yggdrasil is “the friend of the clear sky,”[5] so tall that its crown is above the clouds. Its heights are snow-capped like the tallest mountains, and “the dews that fall in the dales” slide off of its leaves.[6] Hávamál adds that the tree is “windy,” surrounded by frequent, fierce winds at its heights. “No one knows where its roots run,”[7] because they stretch all the way down to the underworld, which no one (except shamans) can see before he or she dies. The gods hold their daily council at the tree.[8]

Numerous animals are said to live among Yggdrasil’s stout branches and roots. Around its base lurk the dragon Nidhogg and several snakes, who gnaw at its roots. An unnamed eagle perches in its upper branches, and a squirrel, Ratatoskr (“Drill-Tooth”[9]), scurries up and down the trunk conveying the dragon’s insults to the eagle and vice versa. Meanwhile, four stags – Dainn, Dvalinn, Duneyrr, and Durathror – graze on the tree’s leaves.[10]

Amusing though some of these animals and their activities may be, they hold a deeper significance: the image of the tree being nibbled away little by little by several beasts expresses its mortality, and along with it, the mortality of the cosmos that depends on it.[11]

The Old Norse sources provide vivid but contradictory accounts of the number and arrangement of the roots and wells beneath the base of Yggdrasil’s trunk.

According to the poem Grímnismál, Yggdrasil has three main roots: one planted in Midgard, the world of mankind; one in Jotunheim, the world of the giants; and one in Hel, the underworld.[12] Völuspá mentions only one well beneath the tree: the Well of Urd (Urðarbrunnr, “Well of Fate“).[13]

However, Snorri Sturluson, in his Prose Edda, holds that there are actually three wells beneath the tree, one for each of its roots. The Well of Urd, according to him, is not below Yggdrasil, as it is in Völuspá – it’s actually in the sky, and the root that grows out of it bends upward into the sky (!). The Well of Urd is where the gods hold their daily council meetings. The second well is called Hvergelmir (perhaps “Bubbling Cauldron”[14] or “Roaring Kettle”[15]), and it’s the body of water beneath the second root, which stretches into Niflheim, the world of primal ice. This is the root that Nidhogg chews. The third well is that of the wise being Mimir, and it and its root lie in the realm of the giants.[16]

Here as elsewhere, Snorri is probably introducing an artificial systematization of his own invention that didn’t exist in the Viking Age (Snorri wrote centuries thereafter). However, some of the elements he includes may have been drawn from legitimate sources that are now lost to us. For instance, Yggdrasil was sometimes called Mímameiðr, “Post of Mimir,”[17] which demonstrates that there was some particular connection between Mimir and the tree – and surely also the well that’s frequently mentioned in connection with Mimir.

But what about the Nine Worlds themselves? How are they arranged around Yggdrasil? The Old Norse sources never tell us – and, for that matter, they never tell us which worlds comprise the Nine in the first place. Given the lack of systematization or codification that characterizes all of Norse mythology and religion, and the tolerance for fluidity, ambiguity, and even contradiction that it implies, it’s doubtful that there was ever a “map” or diagrammatic image of the Nine Worlds and their arrangement in which all of the pagan Norse believed. (All – all – of the pictures you’ll find online are at best speculative and unverifiable.)

Nevertheless, there are some clues in the sources that might enable us to construct a tentative and partial schema of where some of the Nine Worlds would have been generally thought to be located. They seem to have been arranged along two axes, one vertical, the other horizontal. The vertical axis would correspond to Yggdrasil’s trunk, with Asgard in the highest branches, Midgard on the ground at the tree’s base, and Hel underground amongst the tree’s roots. The horizontal axis would be based on the distinction the Vikings made between the innangard and utangard. Thus, Asgard would be right over the trunk of the tree, Midgard around the trunk (and therefore in the “middle” on both of these axes), and Jotunheim would surround Midgard and thereby be that much more distant from the trunk. As for the other worlds: who knows?

In any case, we can see how vital to the Norse worldview Yggdrasil was felt to be by the number of earthly trees the Vikings treated as representations of the great world-tree. Adam of Bremen describes a particularly majestic one near the Temple of Uppsala in Sweden. Farmsteads were customarily designed around such a tree, making the farmstead a miniature reproduction of the sacred spiritual cosmos.[18]

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References:

[1] The Poetic Edda. Völuspá, stanza 47.

[2] Simek, Rudolf. 1993. Dictionary of Northern Mythology. Translated by Angela Hall. p. 375.

[3] The Poetic Edda. Völuspá, stanzas 19, 47; Grímnismál, stanzas 35, 44.

[4] The Poetic Edda. Fjölsvinnsmál, stanzas 19, 20.

[5] The Poetic Edda. Völuspá, stanza 27.

[6] Ibid. Stanza 19.

[7] The Poetic Edda. Hávamál, stanza 138.

[8] The Poetic Edda. Grímnismál, stanzas 29-30.

[9] Simek, Rudolf. 1993. Dictionary of Northern Mythology. Translated by Angela Hall. p. 261.

[10] Ibid. p. 375.

[11] Turville-Petre, E.O.G. 1964. Myth and Religion of the North: The Religion of Ancient Scandinavia. p. 279.

[12] The Poetic Edda. Grímnismál, stanza 31.

[13] The Poetic Edda. Völuspá, stanza 19.

[14] Simek, Rudolf. 1993. Dictionary of Northern Mythology. Translated by Angela Hall. p. 166.

[15] Turville-Petre, E.O.G. 1964. Myth and Religion of the North: The Religion of Ancient Scandinavia. p. 279.

[16] Snorri Sturluson. The Prose Edda. Gylfaginning, chapter 14.

[17] Turville-Petre, E.O.G. 1964. Myth and Religion of the North: The Religion of Ancient Scandinavia. p. 279.

[18] Simek, Rudolf. 1993. Dictionary of Northern Mythology. Translated by Angela Hall. p. 375-376.