Sumer, in the south of what is now Iraq, is celebrated as the region in which writing was invented and the world’s earliest urban civilization developed. Temples, as the institutions within which writing is first attested and as the symbolic centers of cities, played a major role in these developments. In addition, a rich and varied body of religious literature was written in Sumerian, bringing order to the world, explaining events within it, and mediating between the human and divine domains. Temples had interrelated functions as the earthly residences of deities and as administrative centers responsible for receiving and redistributing various types of commodities, and much of the religious literature is inseparably related to concepts of kingship. Sumerian religion thus constitutes a complex nexus of what are, from our perspective, theological, socio-economic, and political concerns.
Briefly it can be described as a polytheistic religion, with a strong belief in the efficacy and necessity of ritual, which expressed human dependence on the divine while at the same time enabling a reciprocal relationship between the two. The principal members of the pantheon were anthropomorphic and had joint roles, on a local level being identified with particular cities and on a regional level contributing to the cultural continuity that united Sumer. The pantheon was fluid and, paralleling the human form of deities, was organized on the same principles as human institutions. It was this fluidity that enabled the pantheon to develop, possibly having its origins in speculation about the physical universe, and subsequently expanding to include deities of pastoral and arable farming, and then of skills such as metal working and writing, as well as of objects symbolizing political status, divine patronage thus stimulating and reinforcing socio-economic and political change.