The settlement landscape of early Mesopotamia was characterized by great cities thathoused great masses of people, kings and priests, and the gods themselves. From the Late Uruk period to the end of the Old Babylonian period (c.3500 to 1500 BC), Mesopotamian cities contained all of the material manifestations of civilization that have fascinated archaeologists and epigraphers: palaces and temples with traditions of high art, administrative organization, and monumental architecture. These material remains gave clues to social and political institutions and their roles in maintaining urban society. The spatial scale of the settlement, on the other hand, reveals the extent to which these institutions successfully maintained social cohesion among the diverse kin and ethnic groups within the cities. In their absence, settlements inevitably split apart as disputes emerged that could not be resolved except via spatial distance between feuding parties. Such cycles of growth and fission in individual settlements had been ongoing since the start of sedentism in the Neolithic, until the fourth millennium BC.