The Volundarkvida, one of the heroic poems collected in the Poetic Edda, opens with the specific, named telling that scholars treat as the earliest surviving Germanic-language version of the swan maiden motif. Three swan-maidens fly down to a lake and remove their swan-garments to rest and spin on the shore; three brothers, among them the smith Volund, come upon them, seize the discarded garments, and each brother takes one of the women as a wife. The poem gives one of the three a name, Alvit, and states plainly that the women stayed nine years before flying off again to seek battles, a detail that marks these particular swan-maidens as valkyrie-adjacent figures in the wider Norse cosmology rather than as ordinary fairy brides, since seeking out battles is valkyrie work specifically.
The nine-year span and the eventual, seemingly inevitable departure distinguish the Volundarkvida account from many later folk versions of the same motif, where the husband's theft and concealment of the skin is the entire engine of the marriage's continuation and the wife's return to bird form happens the moment the skin is recovered. Here the departure reads less as an escape from captivity and more as these particular swan-women returning to a duty, seeking battles, that was always going to call them away regardless of what became of their garments, which is one reason folklorists treat the Norse telling as an older, more mythologically embedded version of a motif that later spread into a simpler fairy-tale shape across the rest of Eurasia.