Mjolnir (also spelled Mjollnir), in Norse mythology, the magic hammer of the thunder god, Thor. Mjolnir (Miller), produced lightning bolts and was Thor's indispensable weapon against the enemies of gods and men. With it he was invincible in battles with frost giants, mountain giants, hill ogres, trolls, and other monsters and demons that threatened heaven and Earth. After being thrown, the hammer would return, like a boomerang, to Thor's hand. He had a pair of magic iron gauntlets that he always wore when wielding Mjolnir, since without them he would be unable to grasp the powerful hammer shaft. The Norse people believed that when the ground was struck by lightning, Thor had sent his hammer crashing to the earth.
Mjolnir was forged by a dwarf named Sindri. While he was creating it, Loki, the trickster fire god, disguised himself as a fly and attempted to interfere with Sindri's work by buzzing around him. As a result, Mjolnir's handle was unusually short. Nevertheless, a blow from Thor's hammer was so powerful that it would result in instant death.
Although Mjolnir could be the bringer of death, it was also a symbol of life and fertility in connection with Thor's influence over the rains and, by extension, good crops. It would bring blessings during marriage by keeping evil powers away from the wedding couple and by promising fecundity to the bride. The image of Thor's hammer has been found on many funerary stelae, rock engravings, and stones that bear runic inscriptions. During the early Christian era in Scandinavia, it may also have been used as a sign of protest against the law that only the cross of Christ could be portrayed on monuments.
As mighty and strong as Thor was, he was almost powerless without Mjolnir. In one story, he woke one day to find that his hammer had been stolen by a giant named Thrym (see the Theft of Thors Hammer), who demanded the hand of the goddess Freya in exchange for the hammer's return. The gods devised a plan to trick the giant: Thor, dressed in Freya's clothing, veil, and golden necklace, went to Thrym's palace, along with the trickster fire god Loki, disguised as Freya's maidservant. Thrym set out a banquet for the wedding. When Mjolnir was brought in and set on the bride's knees for the customary ritual consecration, Thor threw off the disguise, grabbed the hammer and used it to strike down Thrym and all the wedding party ..