Under the name Heiðr (“Bright”), the Vanir Goddesscame to , the home of the Aesir. The Aesir were quite taken by her magical powers and zealously sought her services. But soon they realized that their values of honor, kin loyalty, and obedience to the law were being pushed aside by the selfish desires they sought to fulfill with the witch’s magic. Blaming Freya for their own shortcomings, the Aesir called her “Gullveig” (“Gold-greed”) and attempted to murder her. Three times they tried to burn her, and three times she was reborn from the ashes.
Because of this, the Aesir and Vanir came to hate and fear one another, and these hostilities erupted into war. The Aesir fought by the rules of plain combat, with weapons and brute force, while the Vanir used the subtler means of magic. The war went on for some time, with both sides gaining the upper hand by turns.
Eventually the two tribes of divinities became weary of fighting and decided to call a truce. As was customary among the ancient Norse peoples, the two sides agreed to pay tribute to each other by sending hostages to live among the other tribe. Freya,, and of the Vanir went to the Aesir, and and went to the Vanir.
Njord and his children seem to have lived more or less in peace in Asgard. Unfortunately, the same couldn't be said of Hoenir and Mimir in. The Vanir immediately saw that Hoenir was seemingly able to deliver incomparably wise advice on any problem, but they failed to notice that this was only when he had Mimir in his company. After Hoenir responded to the Vanir’s entreaties with the unhelpful “Let others decide” one too many times, the Vanir thought they had been cheated in the hostage exchange. They beheaded Mimir and sent the severed head back to Asgard, where the distraught chanted magic poems over the head and embalmed it in herbs. Thus preserved, Mimir’s head continued to give indispensable advice to Odin in times of need.
The two tribes were still weary of fighting a war that was so evenly-matched, however. Rather than renewing their hostilities over the misunderstanding, each of the Aesir and Vanir came together and spat into a cauldron. From their saliva they created, the wisest of all beings, as a way of pledging sustained harmony.
In the God of War series
Prelude to War
After years of simmering hostilities between the Aesir and Vanir Gods, the Vanir Goddess Freya attempted to broker diplomacy between the two pantheons. Traveling to Asgard, Freya taught the Aesir how to use magic to harvest their crops, producing food for the entire realm. However, once the crops began to die, the Aesir blamed Freya's brother Freyr, citing his magic as unpredictable. As a result, Freyr was tortured and nearly killed at the Aesir's hands before escaping back to Vanaheim. Enraged, the Vanir swore revenge against Asgard.
Assault on Vanaheim
After a series of skirmishes between the two sides, Odin; the head of the Aesir; assembled a large army and marched them towards Vanahemin. Though the Aesir initially dominated the battle through brute force and Odin's leadership, they were eventually repelled by the Vanir's magic.
With both Asgard and Vanaheim ravaged by the war, both sides found themselves locked in a stalemate. With seemingly no end to the conflict in sight, Odin's advisor Mimir was made to be the arbiter between the warring Gods. Mimir eventually settled on a peaceful solution in which Odin would marry Freya, uniting the two pantheons as one.
Though Odin readily agreed to the marriage, Freya still harbored resentment against him due to the torture he inflicted on Freyr. In the end though, Freya eventually agreed to the union, believing it would cause true peace between the realms. However, this act was met with disgust from her fellow Vanir, who saw it as a betrayal. As a result, Freya was banished from Vanaheim, forbidden to return.
Although she missed her home, Freya was happy in Asgard. She taught her husband magical Vanir spells, and even found a new sense of purpose with the birth of her son Baldur. However, Odin eventually grew paranoid of the Jötnar, believing they would be responsible for bringing about the apocalyptic Ragnarök. Assuming Ragnarok could be prevented if all the Jötunn were to be killed, Odin conditioned the dwarves Brok and Sindri to create the hammer Mjölnir, which he bestowed to his son Thor. Under Odin's command, Thor used Mjölnir to slaughter the Giants across the realms.
Horrified by the cruelty of Odin, Freya attempted to flee Asgard. However, upon being caught by Odin, she was stripped of her fighting spirit, leaving her unable to raise a hand against anyone, even in self-defense. Odin then proceeded to expel Freya from Asgard, leaving her permanently trapped in Midgard.