According to the Völsunga saga, Brynhildr is a shieldmaiden and seemingly valkyrie who is the daughter of Budli. She was ordered to decide a fight between two kings, Hjalmgunnar and Agnar, and knew that Odin preferred the older king, Hjalmgunnar, yet she decided the battle for Agnar. For this Odin condemned her to live the life of a mortal woman, and imprisoned her in a remote castle behind a wall of shields on top of mount Hindarfjall, where she sleeps in a ring of flames until any man rescues and marries her. The hero Sigurðr Sigmundson (Siegfried in the Nibelungenlied), heir to the clan of Völsung and slayer of the dragon Fafnir, entered the castle and awoke Brynhildr by removing her helmet and cutting off her chainmail armour. The two fell in love and Sigurðr proposed to her with the magic ring Andvaranaut. The Völsunga saga also describes a subsequent encounter between Sigurðr and Brynhildr at Hlymdale, the home of Brynhildr's brother-in-law, Heimir. There Sigurðr declared his love for the shieldmaiden after spotting her in her tower. Promising to return and make Brynhildr his bride, Sigurðr then headed for the court of Gjuki, the King of Burgundy. Following Sigurðr's departure, Brynhildr was visited by Gudrun, the daughter of Gjuki, who sought her aid in interpreting a dream. This dream presaged Sigurðr's betrayal of Brynhildr and marriage to Gudrun.
In the kingdom of the Burgundians, Gjuki's wife, the sorceress Grimhild, wanting Sigurðr married to her daughter Gudrun (Kriemhild in Nibelungenlied), prepared a magic potion that made Sigurðr forget about Brynhildr. Sigurðr soon married Gudrun. Hearing of Sigurðr's encounter with the valkyrie, Grimhild decided to make Brynhildr the wife of her son Gunnar (Gunther in the Nibelungenlied). Gunnar, having gained the consent of Heimir, then sought to court Brynhild, but was stopped by a ring of fire around the castle. He tried to ride through the flames with his own horse and then with Sigurðr's horse, Grani, but still failed. Sigurðr then exchanged shapes with him and entered the ring of fire. Sigurðr (disguised as Gunnar) claimed Brynhildr's hand, and they stayed there three nights. However, Sigurðr laid his sword between them (meaning that he did not take her virginity before giving her to the real Gunnar). Sigurðr also took the ring Andvaranaut from her finger and later gave it to Gudrun. Gunnar and Sigurðr soon returned to their true forms, and Brynhildr married Gunnar.
However, Gudrun and Brynhild later quarreled over whose husband was greater, Brynhildr boasting that Gunnar had been brave enough to ride through the flames. Gudrun revealed that it was actually Sigurðr who rode through the ring of fire, and Brynhildr became enraged. Sigurðr, remembering the truth, tried to console her, but to no avail. Brynhildr plotted revenge by urging Gunnar to kill Sigurðr, accusing that he took her virginity on Hidarfjall, which he swore not to do. Gunnar and his brother Hogni (Hagen in the Nibelungenlied) were afraid to kill him themselves, as they had sworn oaths of brotherhood to Sigurðr. They incited their younger brother, Gutthorm, to kill Sigurðr, by giving him a magic potion of enragement, and Gutthorm murdered Sigurðr in his sleep. As he was dying, Sigurðr threw his sword at Gutthorm, killing him. (some Eddic poems say Gutthorm killed him in the forest south of the Rhine, also while resting).
Brynhildr herself killed Sigurðr's three-year-old son, and then she willed herself to die. When Sigurðr's funeral pyre was aflame, she threw herself upon it – thus they passed on together to the realm of Hel.
However, in some Eddic poems such as Sigurðarkviða hin skamma, Gunnar and Sigurðr lay siege to the castle of Atli, Brynhildr's brother. Atli offers his sister's hand in exchange for a truce, which Gunnar accepts. However, Brynhildr has sworn to marry only Sigurðr, so she is deceived into believing that Gunnar is actually Sigurðr.
According to the Völsunga saga, Brynhildr bore Sigurðr a daughter, Aslaug, who later married Ragnar Lodbrok.
In the Eddic poem Helreið Brynhildar (Bryndhildr's ride to Hel), Brynhildr on her journey to Hel encounters a gýgr (giantess) who blames her for an immoral livelihood. Brynhildr responds to her accusations:
In the Nibelungenlied, Brunhild (or Prunhilt) is instead the queen of Iceland. Gunther overpowers her in three warlike games with the help of Siegfried – equipped with an invisibility cloak. First, Brunhild throws a spear, that three men can only barely lift, towards Gunther, but the invisible Siegfried diverts it. Second, she throws a boulder, that requires the strength of twelve men to lift, twelve fathoms. Finally, she leaps over the same boulder. However, Gunther, with Siegfried's help, defeats Brunhild in these games, and takes her as his wife.
On their wedding night, Brunhild refuses to yield her virginity to Gunther, and instead ties him up and suspends him from the ceiling of their chamber. Siegfried (again invisible) violently subdues Brunhild, by cracking her bones and taking her girdle and ring. Following this episode, Brunhild loses her supernatural strength and becomes a devoted wife to Gunther.
Later, in front of the Worms Cathedral, Brunhild enters into an argument with Siegfried’s wife Kriemhild regarding their husbands’ relative prestige. Brunhild believes Siegfried to be nothing more than a lowly vassal of Gunther’s, but Kriemhild reveals the deception and humiliates Brunhild by showing her the ring and girdle.
The Nibelungenlied also differs from Scandinavian sources in its silence on Brunhild's fate; she fails to kill herself at Siegfried's funeral, and presumably survives Kriemhild and her brothers.
Though the cycle of four operas is titled Der Ring des Nibelungen, Richard Wagner in fact took Brünnhilde's role from the Norse sagas rather than from the Nibelungenlied. Brünnhilde appears in the latter three operas (Die Walküre, Siegfried, and Götterdämmerung), playing a central role in the overall story of Wotan's downfall.
In Wagner's tale, Brünnhilde is one of the valkyries, who are born out of a union between Wotan and Erda, the personification of the earth. In Die Walküre Wotan initially commissions her to protect Siegmund, his son by a mortal mother. When Fricka protests and forces Wotan to have Siegmund die for his adultery and incest, Brünnhilde disobeys her father's change of orders and takes away Siegmund's wife (and sister) Sieglinde and the shards of Siegmund's sword, Nothung. She manages to hide them, but must then face the wrath of her father who is determined to make her mortal and put her into an enchanted sleep to be claimed by any man who happens across her. Brünnhilde argues that what she did was in obeyance of the god's true will and does not deserve such a fate. He is eventually persuaded to protect her sleep with magical fire, sentencing her to await awakening by a hero who does not know fear.
Brünnhilde does not appear again until near the end of the third act of Siegfried. The title character is the son of Siegmund and Sieglinde, born after Siegmund's death and raised by the dwarf Mime, the brother of Alberich who stole the gold and fashioned the ring around which the operas are centered. Having killed the giant-turned-dragon Fafnir, Siegfried takes the ring and is guided to Brünnhilde's rock by a bird, the blood of Fafnir having enabled him to understand birdsong. Wotan tries to stop him but he breaks the God's spear. He then awakens Brünnhilde.
Siegfried and Brünnhilde appear again at the beginning of Götterdämmerung, at which point he gives her the ring and they are separated. Here again Wagner chooses to follow the Norse story, though with substantial modifications. Siegfried does go to Gunther's hall, where he is given a potion to cause him to forget Brünnhilde so that Gunther may marry her. All this occurs at the instigation of Hagen, Alberich's son and Gunther's half-brother. The plan is successful, and Siegfried leads Gunther to Brünnhilde's rock. In the meantime she has been visited by her sister valkyrie Waltraute, who warns her of Wotan's plans for self-immolation and urges her to give up the ring. Brünnhilde refuses, only to be overpowered by Siegfried who, disguised as Gunther using the Tarnhelm, takes the ring from her by force.
As potion-enchanted Siegfried goes to marry Gutrune, Gunther's sister, Brünnhilde sees that he has the ring and denounces him for his treachery. Still rejected, she joins Gunther and Hagen in a plot to murder Siegfried, telling Hagen that Siegfried can only be attacked from the back. So Gunther and Hagen take Siegfried on a hunting trip, in the course of which Hagen stabs Siegfried in the back with a spear. Upon their return, where Hagen kills Gunther in a dispute over the ring, Brünnhilde takes charge, and has a pyre built in which she is to perish, cleansing the ring of its curse and returning it to the Rhinemaidens. Her pyre becomes the signal by which Valhalla and all the gods also perish in flames.
Brynhildr may be inspired by the Visigothic princess Brunhilda of Austrasia, who married Merovingian king Sigebert I in 567.The expression "It ain't over till the fat lady sings" is a reference to Brünnhilde's famous immolation scene in Götterdämmerung.
The cartoon character Bugs Bunny disguised himself as "Bwunhilde" to fool Elmer Fudd (depicted as the demigod Siegfried) in What's Opera, Doc?.
The eponymous character from the syndicated comic strip Broom-Hilda.
The Marvel Comics superheroine Valkyrie (also known as Brunnhilde) appears to have been loosely based on Brynhildr.
In the DC Multiverse, the world of Earth-10 (an alternate Earth ruled by the Nazis) contains a super-powered character named Brunhilde, who is that Earth's counterpart of Wonder Woman.
In the 2005 TV epic Dark Kingdom: The Dragon King, American actress Kristanna Loken played Brunhild in an adaptation of the Nibelungenlied saga.
In Season 6 of the popular TV series Xena: Warrior Princess, the character Brunhilda was played by Brittney Powell in three feature episodes: The Rheingold, The Ring and The Return of the Valkyrie.
In the Final Fantasy video game series, various characters and objects share Brynhildr as their namesake.
In the video game Age of Empires: Mythologies, Brunnhilde is a playable Hero Unit.
In the anime Overman King Gainer, Brunhilde is the legendary Overman of Meeya Laujin. She had the ability to create "Black hole".
In the video game Odin Sphere, some parts of the game show the same characteristics as this story. There is the valkyrie called Gwendolyn who after going against her father Odin, and is sentenced to the worst punishment for valkyries - to be married and cast away from the battlefield. She is given over to a dark knight called Oswald, who was raised by a fairy and the grandson to a king. After killing the dragon and retrieving the ring of Titrell, Oswald finds Gwendolyn in a castle asleep. Finding her there he kisses her and she awakes falling in love with him. This is where he gives her the ring and they starting living in the castle together. Through other perils they stay together with either a happy or sad ending depending on how the game is played.
In the online video game World of Warcraft, there is an all-female town in the center of the Storm Peaks in Northrend called Brunnhildar Village.
In the video game Monster Hunter, there is a sword named Brünhild, an apparent reference to Brunhilde.
In the video game Ragnarok Online, there is a piece of armor called Brynhild.
In the Italian comic book Martin Mystère, Brunhilde was condemned by Odin to spend eternity in Hindarfjall because she disobeyed his order to marry Loki, the god of fire. Later, she was freed by the hero Sigurd, who gave her the Ring of the Nibelungs. After Sigurd's death, Brunhilde returned to Hindarfjall where she died many years later. In 2005, Loki created a clone of Brunhilde, but the clone had the body of a grown woman and yet still had the mind of a child. Loki then made an alliance with Morgana le Fay and helped her to obtain the sword of Beowulf; in return, Morgana restored the cloned Brunhilde's mind. But like the original Brunhilde, the clone also hated Loki and escaped from his laboratory. Later the cloned Brunhilde entered Walhalla with Aslaug, the daughter of the original Brunhilde. In Walhalla, the cloned Brunhilde was reunited with Sigurd.
Written and directed by Hayao Miyazaki, the Japanese animated movie Ponyo, whose setting and story were partially inspired by Richard Wagner's opera Die Walküre, portrays a small goldfish with magical powers named Brunhilde, who only after meeting a human boy adopts the name "Ponyo".
The wife of the titular hero in Quentin Tarantino's Django Unchained was named Broomhilda von Schaft by her original German owners. Django's mentor, Dr. King Schultz, tells Django the story of Brunhilde from folklore.
In the webcomic Gunnerkrigg Court, Brynhildr was once a student of the court. Other characters refer to her as "Brinnie". According to a forum post by the author, she was sent to Earth for disobeying Odin.
The anime and manga Brynhildr in the Darkness by Lynn Okamoto
In the 2013 TV series Vikings, Princess Aslaug, Ragnar Lothbrok's second wife, claims to be the daughter of the shieldmaiden Brynhildr and the dragonslayer Sigurd.
In the Anime/Manga The Testament of Sister New Devil The Main Character Toujou Basara carries an ancient spirit capturing sword named Brynhildr.
In the mobile game Fate/Grand Order she is one of the limited servant and she belongs to the Lancer class.
In the Nintendo 3DS game Fire Emblem Fates, there is a magic tome named Brynhildr.
In the light novel The Ending Chronicle, there is a long-lived witch called Brunhild Schild.