One of the most famous objects in Norse mythology, Mjölnir was the hammer wielded by Thor, god of storms and thunder, and was his most potent weapon in battles against the enemies of gods and humans. But Mjölnir represented more than severe weather and violence. In the extant myths of the Norse people and in the archaeological record alike, Mjölnir seems to have had several meanings. From its creation by dwarves to Bronze Age rock carvings, through the Christian conversion of Scandinavia to Thor's dressing as a bride after its theft by a giant, and into the mythic aftermath of Ragnarök, Mjölnir's symbolism reverberated through time. Even in the modern Western world, Mjölnir can represent, among other things, a weapon for the worthy, a sign of belief, and an emblem of hate.

The name Mjölnir, also spelled Mjǫllnir, undoubtedly comes from the Old Norse language in which the Eddas and sagas were written, but the etymology of the name is still a matter of scholarly debate. In his Dictionary of Northern Mythology, Rudolf Simek notes that the name could relate to the Old Slavic mlunuji or the Russian molnija, meaning "lightning," which might lead to the interpretation that Mjölnir means "the one who makes lightning." Simek offers an alternate interpretation according to which Mjölnir means "the shining lightning weapon" and connects the hammer's name with the Old Norse word mjǫll, meaning "new snow," or the Icelandic word mjalli, meaning "white color." Finally, Simek mentions that, in earlier scholarship, Mjǫllnir was connected with the Gothic malwjan and Old Norse mala, meaning "to grind," and was interpreted as meaning "the grinder."

According to the Prose Edda, written by Icelandic poet, historian, and politician Snorri Sturluson (1179 to 1244), Mjölnir was crafted by the dwarven brothers Brokkr and Sindri, alternatively known as Eitri. The dwarven brothers toiled to make the hammer in order to win a wager with Loki, and despite the trickster's best efforts to derail its creation, Mjölnir was completed with only one defect, a very short handle. Despite its small flaw, Mjölnir won the wager for the dwarven brothers, resulting in a punishment for Loki, possibly represented on the Snaptun Stone. According to the section titled Skáldskaparmál in the Prose Edda, Mjölnir can be thrown to produce thunder and lightning and will return to Thor's hand in the manner of a boomerang, meaning the hammer could be wielded in hand and used as a projectile. Ironically, the Vikings do not seem to have used hammers as weapons, favoring instead knives, axes, spears, bows, and swords. From the time of its creation, Mjölnir seems to be an exceptional object with unique applications for its use.

While Snorri provides a narrative of Mjölnir's creation in myth, archaeologists have found carvings of hammers that attest to the ritual significance of hammer-wielding figures dating from the Bronze Age (circa 2000 to 700 BCE). Simek writes:

Mjǫllnir does not only serve as a mythical divine weapon…rock carvings of axe or hammer-bearing god-like figures show, it played a role as a consecratory instrument early on, probably in a fertility cult.

(219)

Moreover, Simek mentions that Mjölnir played a role in the blessing and consecration of marriages in rock carvings from this time period, further attesting to the hammer as a symbolic object in the minds of Bronze Age peoples of Scandinavia. The Poetic Edda, written sometime in the 1270s but based on prior oral tradition, includes a poem called Thrymskvida (Old Norse: Þrymskviða) in which Mjölnir is invoked to bless a marriage. In this case, it is Thor's marriage to a male giant named Thrym.

At the beginning of the poem, Thor awakes to find Mjölnir missing. Distressed, he calls to Loki, who immediately deduces that it was likely the giant Thrym who stole the hammer. When Loki speaks to Thrym to see what he wants for the return of Mjölnir, the giant says that he has hidden the hammer and will not return it unless Freya comes to Jötunheim, land of the giants, to become his bride. When Loki delivers this news, Freya flatly refuses, and Heimdall, watchman of the gods, devises a plan for Thor to dress as Freya and retrieve Mjölnir himself. Despite Thor's protests, the absence of Mjölnir is a desperate situation and calls for desperate action. In one of the most memorable scenes of the Poetic Edda, the gods dress Thor as bride-to-be Freya, arraying him in the symbols associated with the goddess and with marriage and womanhood in Norse culture, including a veil, jewelry, and keys. Loki joins Thor as his handmaiden, and they make their way to the home of Thrym in the land of the giants. After Loki provides justification for Thor's terribly unladylike table manners and burning red eyes, Thrym calls for Mjölnir: "Bring in the hammer, to hallow the bride, lay there Mjöllnir on the maiden's lap, hallow us together by the hand of Vár" (Orchard, 101). As soon as the hammer is returned to him, Thor proceeds to slaughter Thrym and all of his household.

Simek points out that the custom of laying Mjölnir across a bride's lap is not otherwise attested. That being said, it seems to have been an expected part of the narrative for Thor only needing to dress as Freya to be able to retrieve his hammer, and not actually needing to marry the giant to reclaim his weapon. In his Myths of the Pagan North: The Gods of the Norsemen, Christopher Abram notes that Thor's hammer could be associated with protection and fertility. It is possible that the placing of Mjölnir on the bride's lap might recall the Bronze Age use of the hammer in consecration rituals relating to a fertility cult, as mentioned above, though it could have also been an invention for the Thrymskvida narrative. With this connotation and the events of the Thrymskvida in mind, we can turn to the archaeological record to further understand how this weapon and consecration tool became emblematic of Norse beliefs.

Archaeologists have found around 50 silver hammer-shaped pendants in southern and central Scandinavia, though some have been excavated in northern Norway, Poland, England, and Iceland. Scholars believe that these pendants represent a late fashion, starting around the 10th century, and might have been a reaction to the Christian practice of wearing crucifix pendants, though examples of Thor's hammer amulets made of iron, bronze, and amber have also been found that predate those wrought in silver. Abram notes that these earlier examples were likely worn as protective charms symbolic of a widespread cult associated with the hammer-wielding god before the Christian conversion of Scandinavia.

One particular late 10th-century soapstone mold, found at Trendgården in Denmark, features two crucifix molds on either side of a mold of the iconic hammer, demonstrating that, for a time at least, these symbols were simultaneously in demand. In his Children of Ash and Elm: A History of the Vikings, Neil Price mentions several artifacts that provide examples of ambiguous or syncretic religious beliefs in late Viking Age Sweden and Denmark. Notably, this included unique items Price refers to as Thor's hammer crosses, which seem to have been made intentionally hard to read as either a hammer or a crucifix. Price writes, "Such items could have been worn to signal adherence to multiple belief systems, which might have been advantageous according to context" (460). In this case, Mjölnir's status as a symbol seems mutable: the hammer could mimic the crucifix or represent its local opposition depending on the situation.

In a cryptic passage from Vafþruðnismál in the Poetic Edda, the giant Vafthrudnir (Vafþrúðnir) makes it clear that after Thor is killed during the battle of Ragnarök, Mjölnir will be inherited by his sons, Magni and Módi. While it is unclear why Mjölnir, of all the wondrous items possessed by the Aesir, is the only treasure mentioned after the flames of Ragnarök are extinguished, this passage points to its significance: even after the deaths of most of the gods, our extant source accounts for Mjölnir.

Over time, the situations to which Mjölnir is relevant have changed, and its meaning has been adapted to the needs of new interpretations and uses in the modern imagination. In Marvel's interpretation of Thor, the hammer of the thunder god can only be hoisted by those it deems worthy, infusing the object with an agency and morality of its own. In the modern religion of Asatru, the hammer of Thor can be worn as an indication of an individual's belief system. Others might wear and display Mjölnir as a representation of connection to the cultural heritage of the Vikings. Unfortunately, according to the Anti-Defamation League, the hammer has also been appropriated as a symbol of hate by neo-Nazis and other White supremacist groups, who sometimes add swastikas, a similarly appropriated symbol, or other related iconography to the hammer's design.

As we consider Mjölnir in its literary, archaeological, symbolic, and modern contexts, it is clear that Thor's hammer was and is multivalent. It could be used as a devastating weapon, a representation of fertility and natural phenomena, a tool for consecration, or a means of asserting, assigning, or assimilating a belief system. Centuries after the hammer was first carved into stone, the meaning-making of Mjölnir remains relevant in people's lives and imaginations.