Einherjar in the context of Heiðrún

In Norse mythology, a valkyrie (/ˈvælkɪri/ VAL-kirr-ee or /vælˈkɪəri/ val-KEER-ee; from Old Norse: valkyrja, lit. 'chooser of the slain') is one of a host of female figures who guide souls of the dead to the god Odin's hall Valhalla. There, the deceased warriors become einherjar ('single fighters' or 'once fighters'). When the einherjar are not preparing for the cataclysmic events of Ragnarök, the valkyries bear them mead. Valkyries also appear as lovers of heroes and other mortals, where they are sometimes described as the daughters of royalty, sometimes accompanied by ravens and sometimes connected to swans or horses.

Valkyries are attested in the Poetic Edda (a book of poems compiled in the 13th century from earlier traditional sources), the Prose Edda, the Heimskringla (both by Snorri Sturluson) and the Njáls saga (one of the Sagas of Icelanders), all written—or compiled—in the 13th century. They appear throughout the poetry of skalds, in a 14th-century charm, and in various runic inscriptions.

In Norse mythology, Valhalla (/vælˈhælə/ val-HAL-ə, US also /vɑːlˈhɑːlə/ vahl-HAH-lə; Old Norse: Valhǫll [ˈwɑlhɒlː], lit. 'Hall of the Slain') is described as a majestic hall located in Asgard and presided over by the god Odin. There were five possible realms the soul could travel to after death. The first was Fólkvangr, ruled by the goddess Freyja. The second was Hel, ruled by Hel, Loki's daughter. The third was that of the goddess Rán. The fourth was the Burial Mound where the dead could live. The fifth and last realm was Valhalla, ruled by Odin and was called the Hall of Heroes. The masses of those killed in combat (known as the einherjar), along with various legendary Germanic heroes and kings, live in Valhalla until Ragnarök, when they will march out of its many doors to fight in aid of Odin against the jötnar. Valhalla was idealized in Viking culture and gave the Scandinavians a widespread cultural belief that there is nothing more glorious than death in battle. The belief in a Viking paradise and eternal life in Valhalla with Odin may have given the Vikings a violent edge over the other raiders of their time period.

Valhalla is attested in the Poetic Edda, compiled in the 13th century from earlier traditional sources, in the Prose Edda (written in the 13th century by Snorri Sturluson), in Heimskringla (also written in the 13th century by Snorri Sturluson), and in stanzas of an anonymous 10th-century poem commemorating the death of Eric Bloodaxe known as Eiríksmál as compiled in Fagrskinna. Valhalla has inspired innumerable works of art, publication titles, and elements of popular culture and is synonymous with a martial (or otherwise) hall of the chosen dead. The name is rendered in modern Scandinavian languages as Valhöll in Icelandic, while the Swedish and Norwegian form is Valhall; in Faroese it is Valhøll, and in Danish it is Valhal.