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]