Introduction
Baldr is a son of Odin and Frigg, celebrated as the most beautiful, gentle and beloved of all the gods, so fair that light shines from him. His death, brought about through Loki's malice and the one oversight in his mother's otherwise universal protection, is one of the great tragedies of Norse mythology and a decisive omen of the coming end of the world.
This article follows Old Norse mythological tradition, chiefly the Poetic Edda and Snorri Sturluson's Prose Edda, noting where the two sources differ.
Family
The universal oath
Troubled by ominous dreams, Baldr told the other gods of his fears. Frigg travelled the world and won an oath from every substance and creature never to harm him, and the gods amused themselves by throwing weapons at Baldr for sport, since nothing could hurt him.
Death
Loki, learning that Frigg had overlooked the young mistletoe plant, made a dart or spear from it and gave it to the blind god Hodr, guiding his hand to throw it at Baldr during the game. The mistletoe pierced and killed him instantly, to the horror of the assembled gods.
Failed resurrection
Frigg sent Odin's son Hermod to the underworld to plead for Baldr's release. Hel agreed, on condition that everything in existence weep for him; nearly everything did, but one giantess, believed to be Loki in disguise, refused, and Baldr remained among the dead.
Ragnarok and return
Baldr's death is understood throughout the mythology as a direct sign that Ragnarok, the destruction of the world, is approaching. According to the Poetic Edda's Voluspa, after Ragnarok's destruction and renewal, Baldr is prophesied to return from the realm of the dead to help rule the reborn world.