The following discussion of the delta city is confined to the four main 1j9 metropolitan centres of the Eastern Delta, namely Nembe (Brass), Elem Kalabari (New Calabar), Bonny, and Okrika; and excludes the cities of Ode Itsekiri (Warri) in the Western Delta, and Atakpa (Old Calabar) on the Cross River estuary to the east. The four cities seem to have started from a similar cultural and political base-line, and to have responded to similar historical factors such as the overseas trade in slaves, and later, palm oil, with only slight variations. A number of attempts have already been made to define the cities in the Niger Delta. Dike (I956) first studied them in the nineteenth century. He considered them proper states and not tribal states, since citizenship in them was based on residence rather than on kinship. Specifically, he named them city-states, comparable to the Greek city-states, because of the manner in which their political authority radiated from one city to surrounding settlements, and especially to trading posts in the hinterland. Jones (I963) called the cities "trading states". He saw them as creations of the European trade in slaves and palm oil, and as organised, in the main, for the purposes of carrying on overseas trade. The problems of interest in their internal history were, accordingly, the intergroup rivalries between the 'Houses' (trade corporations organised on a lineage model) to be expected in a society organised for commercial competition. Horton (I969, p. 5o) has paid greater attention to the cultural criteria for citizenship, and especially the fact that even bought slaves could become full citizens by becoming fully acculturated: "In positive terms, the identity of New Calabar was seen in the possession of a distinct, isolated settlement area; of autonomy under a distinctive body of laws; and of the possession of a distinctive culture. As in the villages, this definition of identity was essentially open in its implications. Any one who could acquire the culture and pull his weight could become a citizen. As the drum-name of the earth of New Calabar puts it: 'If a dog walks on him, he does not spurn the leg; if a goat walks on him, he does not spurn the leg'." All these views of the Delta city are largely valid, in the aspects of their organisation considered. It is only necessary to sketch in one view that has so far escaped adequate treatment, that is, the religious dimension. Religion, in fact, serves as the ligament holding together the various joints of the social and political structure of each of these Eastern Delta city-states.