Changes

The need for trade was created based on a lack of resources, while location along canals and rivers facilitated the transport of goods. The fertile agricultural area was irrigated with canals, allowing a large population to develop. In essence, low cost transport helped fuel trade growth. Once trade began to make this city wealthy, this then fueled growth further through positive feedback growth. In other words, growth in the city and its trade simply fueled more growth and trade as the city used resources to further invest and grow in other areas, expanding its reach.<ref>Lane, D., Pumain, D., Leeuw, S.v.d. 2009. Introduction, in: D. Lane, D. Pumain, S.v.d. Leeuw, and G. West (Eds.): Complexity Perspectives in Innovation and Social Change. Springer, Berlin, pp. 1-7.</ref> Additionally, other urban areas, as demonstrated through archaeological survey, seem to be growing in this period, suggesting the rise of urbanism began to spread in southern Mesopotamia.<ref> Bob Adams’ extensive surveys in southern Iraq had demonstrated how early urban centers developed. See: Adams, Robert McC. 1981. Heartland of Cities: Surveys of Ancient Settlement and Land Use on the Central Floodplain of the Euphrates. Chicago: University of Chicago Press.</ref> In fact, urbanism in the fourth millennium BC was not simply confined to southern Mesopotamia but also northerly regions.<ref>Oates, Joan, Augusta McMahon, Philip Karsgaard, Salam Al Quntar, and Jason Ur. 2007. Early Mesopotamian urbanism: A new view from the North. Antiquity 81 (2007): 585–600.</ref>

[[File:Anu_district.svg.png|thumbnail|Plan of the Anu District in Uruk, which was initially established in the fourth millennium BC]]

Trade seems to have been so important for urban growth that by the late fourth millennium BC we begin to see the expansion of urban colonies to other regions. One example is the site of Habuba Kabira, a modern day name for an ancient city that was build in the late fourth millennium BC in northern Syria on the Euphrates River. Although writing was still scarce in this period, the city was clearly built by people from southern Mesopotamia, as all of its cultural remains such as architecture, pottery, and other objects indicate the people who settled there did not have cultural markers from the native populations in Syria. Rather, the site of Habuba Kabira represents a colony that was placed next to the Euphrates to control trade coming down to southern Mesopotamia.<ref>Habuba Kabira has been described as a near exact footprint of southern Mesopotamian cities due to its material culture resembling items from that region. See: Strommenger, Eva. 1980. Habuba Kabira: Eine Stadt Vor 5000 Jahren: Ausgrabungen Der Deutschen Orient-Gesellschaft Am Euphrat in Habuba Kabira, Syrien. Sendschrift Der Deutschen Orient-Gesellschaft 12. Mainz am Rhein: von Zabern.</ref> Therefore, it was not simply passive trade that brought goods to southern Mesopotamia but colonies were sometimes established to bring in raw materials.