Óðinn's question to Vafþrúðnir is extremely pertinent: how do we know the myths that (we think) we know? This chapter will consider the sources for Other World encounters in Old Norse myth and legend and the rationale for using them. Unlike religious practice, for which the best sources are often archaeological, mythology is essentially narrative and depends chiefly on written sources. Although there are important sources in both prose and verse, most of the prose works derive their material from older poetry, so it is the poetic tradition whose evidence is usually primary. It can be divided into two poetic genres: eddic and skaldic.

1. Eddic poetry

Most eddic poems are anonymous; their metres and diction are relatively simple, and they present whole myths or segments of myths in narrative, monologue or dialogue form. They are difficult to date, but linguistic evidence suggests that none can be earlier than c. 800; most were probably composed between the mid-ninth century and the mid-thirteenth. They were apparently not written down until the early thirteenth century. Eddic poetry has traditionally been regarded as having a limited ‘canon’ and containing two distinct sets of subject matter: mythological (poems about gods and other supernatural beings) and heroic (poems about legendary human beings). The main body of this ‘canon’ is found in the Codex Regius of the Poetic Edda, where the first eleven poems form what looks like a separate mythological section, although the headings in the manuscript do not make this division explicit.

A few poems found in other manuscripts are traditionally called Eddica Minora, and some editors also categorise these as either mythological or heroic. Usually accepted as mythological are Baldrs draumar, Rígsþula, Hyndluljóð, Grottasǫngr and Svipdagsmál, though the last survives only in post-medieval manuscripts.1 There are also some quotations in Snorra Edda (see section 4 below) from poems which are otherwise lost.