Vanir in the context of "Freyja"

Æsir (Old Norse; singular: áss) or ēse (Old English; singular: ōs) are gods in Germanic paganism. In Old Nordic religion and mythology, the precise meaning of the term "Æsir" is debated, as it can refer either to the gods in general or specifically to one of the main families of gods, in contrast to the Vanir, with whom the Æsir waged war, ultimately leading to a joining of the families. The term can further be applied to local gods that were believed to live in specific features in the landscape – such as fells. The Old English medical text Wið færstice refers to the Ēse, along with elves, as harmful beings that could cause a stabbing pain, although exactly how they were conceived of by the author of the text is unclear.

Áss and its cognate forms feature in many Germanic names, such as Oswald and Ásmundr, and in some place-names in Norway and Sweden. The Æsir further likely give their name to the A-rune, attested in the Elder Futhark, Anglo-Saxon Futhorc and Younger Futhark.

Old Norse religion, also known as Norse paganism, is a branch of Germanic religion which developed during the Proto-Norse period, when the North Germanic peoples separated into distinct branches. It was replaced by Christianity and forgotten during the Christianisation of Scandinavia. Scholars reconstruct aspects of North Germanic Religion by historical linguistics, archaeology, toponymy, and records left by North Germanic peoples, such as runic inscriptions in the Younger Futhark, a distinctly North Germanic extension of the runic alphabet. Numerous Old Norse works dated to the 13th-century record Norse mythology, a component of North Germanic religion.

Old Norse religion was polytheistic, entailing a belief in various gods and goddesses. These deities in Norse mythology were divided into two groups, the Æsir and the Vanir, who in some sources were said to have engaged in war until realizing that they were equally powerful. Among the most widespread deities were the gods Odin and Thor. This world was inhabited also by other mythological races, including jötnar, dwarfs, elves, and land-wights. Norse cosmology revolved around a world tree known as Yggdrasil, with various realms, such as Midgard, where humans live. These involved multiple afterlives, several of which were controlled by a particular deity.

A jötunn (also jotun; plural jötnar; in the normalised scholarly spelling of Old Norse, jǫtunn /ˈjɔːtʊn/; or, in Old English, eoten, plural eotenas) is a type of being in Germanic mythology. In Norse mythology, jötnar are often contrasted with gods (the Æsir and Vanir) and with other non-human figures, such as dwarfs and elves, although the groupings are not always mutually exclusive. The entities included in the jötunn category are referred to by several other terms, including risi, þurs (or thurs) and troll if male and gýgr or tröllkona if female. The jötnar typically dwell across boundaries from the gods and humans in lands such as Jötunheimr.

The jötnar are frequently attested throughout the Old Norse records, with eotenas also featuring in the Old English epic poem Beowulf. The usage of the terms is dynamic, with an overall trend that the beings become portrayed as less impressive and more negative as Christianity becomes more influential over time. Although the term "giant" is sometimes used to gloss the word "jötunn" and its apparent synonyms in some translations and academic texts, this is seen as problematic by some scholars as jötnar are not necessarily notably large.

In Norse mythology, the Æsir–Vanir War was a conflict between two groups of deities that ultimately resulted in the unification of the Æsir and the Vanir into a single pantheon. The war is an important event in Norse mythology, and the implications for the potential historicity surrounding accounts of the war are a matter of scholarly debate and discourse.