This paper had its genesis in an attempt to understand certain aspects of the ancestor cult of the Mpondomise, a Cape Nguni people of the Transkei, South Africa. Like all Southern Bantu, the Mpondomise have only a vague idea of a supreme being and effective ritual behaviour is directed towards the shades of deceased agnatic forebears, the izinyanya. It was immediately obvious that any understanding, particularly of the structural aspects of the cult, depended on a clear picture of the lineage, of what is, in effect, its ‘congregation’ (in the Durkheimian sense). It is an anthropological truism that ancestor cults exhibit to a high degree that congruence between ritual behaviour and social structure emphasized by Durkheim. In strong contrast to the universalistic world religions, recruitment to the cult group is in terms of a kinship idiom, either through birth, marriage, or adoption, the beings to whom worship is directed are highly differentiated and structurally defined, and their sphere of influence is similarly bounded. There is evidence that the ancestor cult is inversely correlated with a highly developed cult of a supreme being and that sacrifice to the manes tends to symbolize commensalism (as one would expect with erstwhile kinsmen) rather than the explicit identification of the worshipper with the offering found, for example, both among the Nuer, with their conceptualization of an omnipotent High God, and, in some of its symbolism at least, in the Christian Eucharist. Be this as it may, ancestor cults have been particularly congenial to the structural interests of modern social anthropologists and the growing number of detailed studies has greatly increased our knowledge of this religious form. It was thus essential, as a preliminary exercise, to define the congregation of the cult, the locus of ritual authority within it, and the relationship of the living members of the group to the dead.