A Vanir named Hogun decided to travel to Asgard. When he arrived, he liked it so much that he decided to stay. He became friends with Asgard's prince, Thor. Thor introduced Hogun to his friends Fandral and Volstagg. The three became good friends, and became the Warriors Three.
After Thor defeated his adopted brother, Loki, by destroying the Bifrost Bridge, all of the Nine Realms were put in danger without the protection of the Asgardians. The Vanir were put in harm's way by Marauders, an army of ragtag pillagers and scavengers. After a three year war, and with the help of the armies of Asgard, the Vanir were able to defend their realm and defeat the Maruders.
The Vanir are, more or less, the genetic cousins of the Asgardians, and therefore share many physical traits and attributes such as their enhanced durability, strength, speed, and longevity. Their appearance is akin to humans and Asgardians, but the Vanir resemble humans of Asiatic decent while the Asgardians resemble humans of European or African decent. The physical characteristics of the Vanir are also not that much different from the Asgardians.
Their culture seems to be different from the Asgardians. While the Asgardians are a warrior, space-faring race, the Vanir are not known to have a history of great battles and rely on the Asgardian armies to defend them and their Realm. They also seem to be less technologically advanced than Asgardians and even humans, living in tents while most of their planet is densely wooded. Throughout the landscape of Vanaheim, various columns and arches can be seen, which presumably have cultural or historical significance.
- In the non-canon video game Thor: God of Thunder, Thor travels to Vanaheim and discovers an old recording archive which reveals the extinction of the Vanir at the hands of Mangog. After that event, the Rock Trolls had taken over their realm, having been banished from Nornheim.
- In Norse mythology, the Vanir are less aggressive than their Asgardian cousins and are known for practicing magic and wisdom, while the Asgardians practice "strength" (war). In the comics and mythology, there is a great Æsir-Vanir War, which was "won" by the Æsir (Asgardians). This might explain their lack of technology and dependence on and close ties with the Asgardians.
- Vanir seems to have been modelled after the Mongols. Aside from their Asiatic looks, they are war-like and live in yurts.