In many non-industrial, non-Western societies, power and prestige are closely linked to the extent of an individual's or group's perceived connection to the supernatural realm, which also explains and validates tangible activities such as economic success, victories in war, or control over lucrative trade. Affines (in-laws), ancestors, and aristocrats, in particular, are connected to the realm of creative cosmological origins (i.e., to Genesis), which accords them distinctive, supernatural powers and gives them a natural and legitimate right to worldly authority. This is the hypothesis that Mary W. Helms pursues in this broadly cross-cultural study of aristocracy in chiefly societies. She begins with basic ideas about the dead, ancestors, affines, and concepts of cosmological origins. This leads her to a discussion of cosmologically defined hierarchies, the qualities that characterize aristocracy, and the political and ideological roles of aristocrats as wife-givers and wife-takers (that is, as in-laws). She concludes by considering various models that explain how societies may develop or define aristocracies.