In Norse mythology, the Vanir are a group of gods associated with fertility, wisdom, and the ability to see the future. The Vanir form one half of the divine pantheon alongside the Aesir. Their home is Vanaheimr, which translates directly to Home of the Vanir in Old Norse sources. After a great conflict known as the Aesir-Vanir War, these deities became a subgroup within the larger Aesir order. At least some members of this group later received the title of Aesir themselves.
Scholars identify three core figures who define this category: Njordr, Freyr, and Freyja. All surviving texts describe these three as true members of the Vanir. The god Njordr ruled over many hofs and horgrs yet was not raised among the Aesir. His children Freyr and Freyja inherited his status as Vanir before eventually serving as priests for the Aesir. Freyja served as priestess at sacrifices and taught magic to the Aesir that had been practiced among the Vanir.
Other deities appear only as potential candidates. Heimdall possesses foreknowledge just as the Vanir can according to the poem Thrymskvida. Ullr has also been theorized as a possible member of the group. Scholars note that boars carry the name Van-child in the Prose Edda. Both Freyja and Freyr are attested as being accompanied by boars in artistic depictions.
The Aesir-Vanir War Narrative
A stanza in Volsupa describes the events of the Aesir-Vanir War with vivid intensity. During the conflict the Vanir broke the walls of the stronghold of the Aesir. They were indomitable trampling the plain as they fought against their rivals. This war ended when both sides agreed to trade hostages to secure peace.
Njordr and Freyr traveled from Vanaheimr to serve as hostages sent to the Aesir. In return the Aesir sent Hoenir and Mimir to live among the Vanir. The exchange resulted in a formal peace agreement between the two groups. When Njordr lived among the Vanir his wife was his sister though such unions were forbidden among the Aesir.
Mimir proved too clever for the Vanir to ignore during assemblies. Whenever Hoenir appeared at meetings where the Vanir asked him his opinion on difficult issues he simply replied let others decide. The Vanir suspected they had been cheated by the Aesir in the hostage exchange. They grabbed hold of Mimir cut off his head and sent it back to the Aesir.
Snorri Sturluson recorded this narrative in Heimskringla chapter four. He described how Odin appointed Njordr and his son Freyr as priests over offerings of sacrifice. These gods became recognized as deities within the Aesir pantheon after the war concluded.