IN SAGA LITERATURE, the motif of the hero's adoption (or fostr) (1) by a giantess (2) recurs frequently, usually with an erotic subtext and particularly in the fornaldarsogur, which have a strong fantasy content including the appearance of supernatural beings and the use of sorcery. (3) The most complete analysis of this motif has been provided by Hilda Ellis (1941), who discusses examples mostly taken from the fornaldarsogur: Hildigunnr in the more recent version of Orvar-Odds saga (fourteenth century), Brana in Halfadanar saga Bronufostra (circa 1300), Mana in Sorla saga sterka (fifteenth century), Yma in Hjalmpers saga ok Olvers (fifteenth century), and Grior in Illuga saga Gridarfostra (fifteenth century). Though mentioning Grior, Ellis herself questions her inclusion in the list (72) because Grior is not a "real" giantess but a queen who has been transformed by sorcery, a motif current in the fornaldarsogur according to Ellis (74), who unfortunately does not mention any other examples. (4) Apart from these, Ellis indicated that Harthgrepa in Saxo Grammaticus's Gesta Danorum (thirteenth century), Heidr in Halfdanar pattr svarta in Flateyjarbok (fourteenth century), and Helga in the more recent Bardar saga Snefellsass (fourteenth century) have a number of elements in common with the fornaldarsogur.
To this list we might also add Hrafnhildr in Ketils saga hoengs (fourteenth century) and other giantesses who do not fall within the category of fostrur but who nevertheless provide assistance to the heroes of the saga literature, often as a result of a more or less explicit sexual attraction. It will suffice to mention Gridr in Eilifr Godrunarson's porsdrapa (late tenth century), Menglod in Orms pattr Storolfssonar (late thirteenth century), Arinnefja in Egils saga einhenda ok Asmundar berserkjabana (fourteenth century), but it appears somewhat more problematic to include Tyr's mother in this list, as described in Hymiskvida, since her descent is unspecified although the parallels with giant fostrur may be taken as evidence of that background. (5) This article is mainly concerned with the possibility of comparing these supernatural fostrur with other literary persone who, while belonging to the human race, play the same role as giantesses and share with them a number of key features. In saga accounts of helpful giantesses, the assistance granted by the fostra to her favored hero is usually important, if not decisive, especially thanks to her supernatural powers, which allow her to rescue humans from apparently desperate situations: almost all of these giant fostrur are explicitly portrayed as using magic.
The sources reveal a close link between giants and magic, which is particularly important in the case of trolls. In fact, the Old Norse name troll may be referred to magical creatures, sorcerers, and witches (Asgeir 1067), and the derived verb trylla means to enchant, or bewitch (Vries 599-600, Asgeir 1066). Modern Scandinavian languages have built on this connection between trolls and magic to the extent that the root of the word has almost entirely replaced the older *gal-, which is preserved only in the Modern Icelandic galinn, the Swedish and Norwegian galen, and the Danish gal, all of which derive from galinn [crazy, out of one's wits], the past participle of the Old Scandinavian gala [to sing, enchant, bewitch] which has the same root as galdr [enchantment; magic] (Asgeir 225).
In Modern Icelandic, the root gala is still vital, and a large number of magical terms derive from galdr (such as galdra [to perform magic or conjuring tricks], galdramadr [magic-user, sorcerer], and galdrakerling or galdranorn [sorceress, witch]); this fact is largely due to rejectino in Modern Icelandic of the Latin loan-word magia, which is accepted in the Continental languages; the connection between sorcery and trolls is still to be found in the Modern Icelandic trylla [to lead to madness] and the past participle trylldr is clearly equivalent togalinn (Asgeir 1066). …