In the Prose Edda book Gylfaginning, Hel is described as the daughter of Loki and Angrboða – a giantess (gýgr, see jötunn) – and thus sister of the Fenrisulfr and the sea serpent Jörmungandr. Since her father is often described as a god, although both his parents were giants, the same might be said of Hel.
When Odin became aware of the existence of Loki's children, he banished them to remote places. He then cast Hel down to her realm in the underworld and gave her authority over all those in the nine worlds who do not die gloriously in battle but of sickness or of old age.
Hon á þar mikla bólstaði ok eru garðar hennar forkunnar hávir ok grindr stórar. Éljúðnir heitir salr hennar, Hungr diskr hennar, Sultr knífr hennar, Ganglati þrællinn, Ganglöt ambátt, Fallandaforað þresköldr hennar er inn gengr, Kör sæing, Blíkjandaböl ársali hennar. Hon er blá hálf en hálf með hörundarlit, því er hon auðkend ok heldr gnúpleit ok grimmlig.
She has great possessions there; her walls are exceeding high and her gates great. Her hall is called Sleet-Cold; her dish, Hunger; Famine is her knife; Idler, her slave; Sloven, her maidservant; Pit of Stumbling, her threshold, by which one enters; Disease, her bed; Gleaming Bale, her bed-hangings. She is half blue-black and half flesh-color (by which she is easily recognized), and very lowering and fierce. |
- Brodeur translation
En þat er at segja frá Hermóði at hann reið níu nætr døkkva dala ok djúpa svá at hann sá ekki fyrr en hann kom til árinnar Gjallar ok reið á Gjallarbrúna. Hon er þökt lýsigulli. Móðguðr er nefnd mær sú er gætir brúarinnar.
||Now this is to be told concerning Hermóðr, that he rode nine nights through dark dales and deep, so that he saw not before he was come to the river Gjöll (or Gjallar-river) and rode onto the Gjöll-Bridge (or Gjallar-bridge); which bridge is thatched with glittering gold. Móðguðr is the maiden called who guards the bridge.|
Hel agrees to release Baldr, but only if every being in the world cries over his death. All do, except for one giantess—sometimes said to be Loki in disguise—and thus Baldr remains in Hel, though he will supposedly be resurrected after Ragnarok.
Viktor Rydberg, in particular, advocated this view. In the book "Our Fathers' Godsaga" he theorizes that the correct name for Loki's daughter is in fact "Leikn" and that, in Christian times, she was confused with Urðr, one of the three Norns and the dís of fate and death. Rydberg's theories are not generally accepted.