But already in the beginning of time, evil powers appear for the purpose of opposing and ruining the good influences from the world of gods upon mankind. Just as Heimdall, "the fast traveler," proceeds from house to house, forming new ties in society and giving instruction in what is good and useful, thus we soon find a messenger of evil wandering about between the houses in Midgard, practicing the black art and stimulating the worst passions of the human soul.
The messenger comes from the powers of frost, the enemies of creation. It is a giantess, the daughter of the giant Hrímnir (Hyndluljóð 32 = Völuspá in Skamma 4), known among the gods as Gullveig and by other names (see Nos. 34, 35), but on her wanderings on earth called Heiðr. "Heid they called her (Gullveig) when she came to the children of men, the crafty, prophesying vala, who practiced sorcery (vitti ganda), practiced the evil art, by witchcraft caused misfortunes, sickness, and death (leikin, see No. 67), and was always sought by bad women."
Thus Völuspá 22 describes her. The important position Heid occupies in regard to the corruption of ancient man, and the consequences of her appearance for the gods for man, and for nature (see below), have led Völuspá's author, in spite of his general poverty of words, to describe her with a certain fullness, pointing out among other things that she was the cause of the first war in the world. That the time of her appearance was during the life of Borgarand his son shall be demonstrated below. In connection with this moral corruption, and caused by the same powers hostile to the world, there occur in this epoch such disturbances in nature that the original home of man and culture - nay, all Midgard - is threatened with destruction on account of long, terrible winters. A series of connected myths tell of this. Ancient artists - forces at work in the growth of nature - personifications of the same kind as Rigveda's Ribhus, that before had worked in harmony with the gods, become foes of Asgard, through the influence of Loki, their work becoming as harmful as it once was beneficent, and seek to destroy what Odin had created (see Nos. 111 and 112). Idunn, with her life-renewing apples, is carried away from Asgard to the northernmost wilderness of the world by Thjazi, and is concealed there. Freyja, the goddess of fertility, is stolen and falls into the power of giants. Frey, the god of harvests, falls sick1 . The giant king Snow and his kinsmen Þorri (Black Frost), Jökull (the Glacier), etc., extend their scepters over Scandia. Already during Heimdall's reign, after his protégé Borgar had grown up, something happens which forebodes these terrible times, but still has a happy issue.
Excerpt from:Investigations into Germanic Mythology, Volume 1 by Viktor Rydberg