The mighty ash-tree Ygdrasil was supposed to support the whole universe. It sprang from the body of Ymir, and had three immense roots, extending one into Asgard (the dwelling of the gods), the other into Jotunheim (the abode of the giants), and the third to Niffleheim (the regions of darkness and cold). By the side of each of these roots is a spring, from which it is watered. The root that extends into Asgard is carefully tended by the three Norns, goddesses who are regarded as the dispensers of fate. They are Urdur (the past), Verdandi (the present), Skuld (the future). The spring at the Jotunheim side is Ymir's well, in which wisdom and wit lie hidden, but that of Niffleheim feeds the adder, Nidhogge (darkness), which perpetually gnaws at the root. Four harts run across the branches of the tree and bite the buds; they represent the four winds. Under the tree lies Ymir, and when he tries to shake off its weight the earth quakes.
Asgard is the name of the abode of the gods, access to which is only gained by crossing the bridge, Bifrost (the rainbow). Asgard consists of golden and silver palaces, the dwellings of the gods, but the most beautiful of these is Valhalla, the residence of Odin. When seated on his throne he overlooks all heaven and earth. Upon his shoulders are the ravens Hugin and Munin, who fly every day over the whole world, and on their return report to him all they have seen and heard. At his feet lie his two wolves, Geri, and Freki, to whom Odin gives all the meat that is set before him, for he himself stands in no need of food. Mead is for him both food and drink. He invented the Runic characters, and it is the business of the Norns to engrave the runes of fate upon a metal shield. From Odin's name, spelt Wodin, as it sometimes is, came Wednesday, the name of the fourth day of the week.
Odin is frequently called Alfadur (All-father), but this name is sometimes used in a way that shows that the Scandinavians had an idea of a deity superior to Odin, uncreated and eternal.
Valhalla is the great hall of Odin, wherein he feasts with his chosen heroes, all those who have fallen bravely in battle, for all who die a peaceful death are excluded. The flesh of the boar Schrimnir is served up to them, and is abundant for all. For although this boar is cooked every morning, he becomes whole again every night. For drink the heroes are supplied abundantly with mead from the she-goat Heidrun. When the heroes are not feasting they amuse themselves with fighting. Every day they ride out into the court or field and fight until they cut each other in pieces. This is their pastime; but when meal-time comes, they recover from their wounds and return to feast in Valhalla.
The Valkyrior are warlike virgins, mounted upon horses and armed with helmets, shields, and spears. Odin, who is desirous to collect a great many heroes in Valhalla, to be able to meet the giants in a day when the final contest must come, sends down to every battle-field to make choice of those who shall be slain. The Valkyrior are his messengers, and their name means "Choosers of the slain." When they ride forth on their errand their armor shed a strange flickering light, which flashes up over the northern skies, making what men call the "Aurora Borealis," or "Northern Lights." (Gray's ode, The Fatal Sisters, is founded on this superstition.)
The following is by Matthew Arnold:
"-----He crew at dawn a cheerful note, To wake the gods and heroes to their tasks And all the gods and all the heroes woke. And from their beds the heroes rose and donned Their arms, and led their horses from the stall, And mounted them, and in Valhalla's court Were ranged; and then the daily fray began, And all day long they there are hacked and hewn 'Mid dust and groans, and limbs lopped off, and blood; But all at night return to Odin's hall Woundless and fresh; such lot is theirs in heaven. And the Valkyries on their steeds went forth Toward earth and fights of men; and at their side Skulda, the youngest of the Nornies, rode; And over Bifrost, where is Heimdall's watch, Past Midgard Fortress, down to Earth they came; There through some battle-field, where men fall fast, Their horses fetlock-deep in blood, they ride, And pick the bravest warriors out for death, Whom they bring back with them at night to heaven, To glad the gods, and feast in Odin's hall." BALDER DEAD
This description of The Funeral of Balder is by William Morris: