Much of the land in and around Mesopotamia was unsuitable for agriculture due to the scarcity of waterways and insufficient rain but provided enough seasonal grass for transhumant herding. The most important animals for pastoralism were sheep and goats, whose growth period coincides with the renewal of vegetation in the winter months. The social structures of seminomadic or fully nomadic pastoralism developed to ensure maximum mobility for herds and people while maintaining internal cohesion. Little is known about these configurations in antiquity due to the fact that the settled population held nomads in contempt. It appears, however, from documents such as the Mari archives, that they were tribally organized, patrilinear, and patriarchal.
The relations between the city dwellers in Mesopotamia and nomadic groups were generally described as problematic in the cuneiform documents, especially at times when waves of nomadic tribespushed into the rural districts, which were normally controlled by the state. Such forced occupations were met by military resistance or even the building of defensive walls, but neither proved effective. Nomadic immigrations into Mesopotamia came mainly from the west, the Arabian peninsula and southern Syria, and to a lesser degree from the Iranian plateau and the Caucasus mountains. The bestrecorded periods of tribal incursions were those of the Amorites in the late third millennium and those of the Arameans in the 12th and 11th centuries B.C.
Such large-scale and violent incursions were not symptomatic of the relations between nomads and the settled in Mesopotamia. Mutually beneficial contacts were the norm; the nomads were allowed to graze their herds on the stubble after the harvests, thus loosening and fertilizing the soil; after planting, the animals could nibble off the first shoots and thus render the plants hardier, encouraging growth. The markets of the cities supplied the necessary articles such as weapons, tools, and jewelry for women. There was an ongoing process of gradual sedentarization for some tribal members, who would maintain social contact with their kin groups and relay new modes of thinking and living. Mesopotamian civilization was thus continuously enriched by the absorption of tribal people. Camelnomadism developed only in the first millennium, after the domestication of the camel.
Historical Dictionary of Mesopotamia. EdwART. 2012.