This thesis demonstrates that there is a compelling link between the ancient northern Bear Cult and Old Norse sagas. This is achieved through analysis of two fornaldarsögur, in terms of ritual framework and the thread of animism which lies under the surface of the narrative. The chosen sagas are the famous Völsungasaga and Hrólfs saga kraka ok kappa hans. This thesis focuses on two episodes in these sagas. In Völsungasaga, analysis is made of the legendary encounter between Sigurd and Fafnir. In Hrólfs saga, the thesis concentrates on Bödvar and Hottr, and their strange experience with the animal that attacks Hrolf's hall. These slaying episodes are examined in light of a scholarly framework for identifying initiation rituals. It is found that ritual combat with a supernatural monster is likely to be based in actual historical practice. The history of this practice is traced back to a cult belief that has been termed Eurasia's oldest religion; the ancient northern Bear Cult. This once spanned the northern hemisphere, but was remarkably preserved in Finno-Karelian oral tradition. Poetry from Finland and Karelia, including the Finnish national epic, the Kalevala, form the comparative material against which the sagas are examined for links to the Bear Cult. This thesis finds that there are compelling connections between the Bear Cult and the slaying episodes in terms of ritual patterns and animist practice. This connection is significant for seeing the slaying episodes as remnants of actual historical practice, and for understanding the origin of some of the motifs and themes in the sagas.