In spite of their origin, Frey and Freyja become to all intents and purposes Aesir.  Frey is to be one of the chief combatants at Ragnaroek, with the fire-giant Surt for his antagonist, and a story is told to explain his defeat:  he fell in love with Gerd, a giant-maid, and sacrificed his sword to get her; hence he is weaponless at the last fight.  Loki alludes to this episode in Lokasenna:  “With gold didst thou buy Gymi’s daughter, and gavest thy sword for her; but when Muspell’s sons ride over Myrkwood, thou shalt not know with what to fight, unhappy one.”  The story is told in full in Skirnisfoer.

Freyja is called by Snorri “the chief Goddess after Frigg,” and the two are sometimes confused.  Like her father and brother, she comes into connexion with the giants; she is the beautiful Goddess, and coveted by them. Voeluspa says that the Gods went into consultation to discuss “who had given the bride of Od (i.e., Freyja) to the giant race”; Thrymskvida relates how the giant Thrym bargained for Freyja as the ransom for Thor’s hammer, which he had hidden, and how Loki and Thor outwitted him; and Snorri says the giants bargained for her as the price for building Valhalla, but were outwitted.  Sir G.W.  Dasent notices in the folk-tales the eagerness of trolls and giants to learn the details of the agricultural processes, and this is probably the clue to the desire of the Frost-Giants in the Edda for the possession of Freyja.  Idunn, the wife of Bragi, and a purely Norse creation, seems to be a double of Freyja; she, too, according to Snorri, is carried away by the giants and rescued by Loki.  The golden apples which she is to keep till Ragnaroek remind us of those which Frey offered to Gerd; and the gift of eternal youth, of which they are the symbols, would be appropriate enough to Freyja as an agricultural deity.

The great necklace Brising, stolen by Loki and won back in fight by Heimdal (according to the tenth-century Skalds Thjodulf and Ulf Uggason), is Freyja’s property.  On this ground, she has been identified with the heroine of Svipdag and Menglad, a poem undoubtedly old, though it has only come down in paper MSS.  It is in two parts, the first telling how Svipdag aroused the Sibyl Groa, his mother, to give him spells to guard him on his journey; the second describing his crossing the wall of fire which surrounded his fated bride Menglad.  If Menglad is really Freyja, the “Necklace-glad,” it is a curious coincidence that one poem connects the waverlowe, or ring of fire, with Frey also; for his bride Gerd is protected in the same way, though his servant Skirni goes through it in his place: 

Skirni.  “Give me the horse that will bear me through the dark magic waverlowe, and the sword that fights of itself against the giant-race.”

Frey.  “I give thee the horse that will bear thee through the dark magic waverlowe, and the sword that will fight of itself if he is bold who bears it.” (Skirnisfoer.)