Tyr – A historical and comparative study of configurations and formations connected to the Old Norse god Tyr. Klas af Edholm   This thesis has two aims. One is a discussion of the history of the study of Old Norse religion and related aspects, centered on how general tendencies within the area of research have affected the interpretations of the god *Tīwaz/Tyr. Thereby, it treats a selection of influential trends of interpretation, and a selection of prominent scholars of the field. The second aim is an empirical and comparative analysis of the Old Norse source material and, to some degree, the continental Germanic, the Baltic, and the other Indo-European material. Tyr has been interpreted according to trends of research in the field; the mythological character has been used as a projection screen of the theories. Already from the beginning, Tyr was interpreted as a sky god; connected to this was the conception of an original high god. The interpretations of Tyr as a sun god, sky god, and/or law god are close related to this high god conception. These interpretations of the god Tyr has built their arguments upon the etymological connection to Indo-European words for ‘heaven, celestial’ and ‘god’, but they have not taken enough consideration of the Old Norse sources. Georges Dumézil interpreted Tyr, according to his système tripartite, as a law god. This understanding of the god has been widely adopted, but cannot be confirmed; the Old Norse material only speaks of Tyr as a war god. The comparative Indo-European etymological material indicates that his function as sky god is archaic, while the martial traits shared with the continental Germanic and Celtic counterparts prove that this characteristic must have evolved early. Tyr (or rather his predecessor *Tīwaz) lost his celestial traits and became an unmitigated war god, and as such we perceive him in the Old Norse religion.