CHAPTER fiVE

Early Mesopotamian Urbanism: How?

The concept of circular and cumulative causation discussed in chapter 3 allows us to visualize a still largely speculative, though ultimately testable, scenario to account for the urban takeoff of southern Mesopotamian societies in the fourth millennium. Following the insights of Jacobs, this scenario focuses on how economic differentiation could have evolved in the south. For heuristic purposes, this hypothetical process is divided here into a number of discrete stages, although substantial over-

laps must be presumed to have existed between them.

The Growth of Early Mesopotamian Urban Economies

The initial stage of the growth of southern economies would have taken place during the late fifth and early fourth millennia (Late Ubaid and Early Uruk periods)—a time when the geographical and environmental framework of southern Mesopotamia created a mosaic of very different but easily exploited resource endowments across what is today the Mesopotamian alluvium. In its northern portions, gravity flow irrigation and increased water tables would have made grain cultivation and horticulture more profitable, whereas areas nearer the gulf were better situated to exploit its biomass-rich marshes, lagoons, and estuaries. Inadvertently, this setting provided the initial impetus for burgeoning trade be-

tween polities exploiting these varied economic resources. Each of these polities would have naturally specialized in the production of a small number of crops or commodities for which it had a comparative advantage, owing to its location within the alluvial ecosystem. Products traded in this initial stage would have included (1) raw wool, woven and dyed textiles, goat-hair products, leather goods, dairy fats, and other pastoral resources distributed by polities situated at the margins of the betterwatered parts of the alluvium, where they would have enjoyed preferential access to pastoral and nomadic groups producing these various commodities; (2) flax-based textiles, garden crops, and grain produced by polities in the northern portion of the Mesopotamian alluvial plain, where the combined flow of the Tigris and the Euphrates made irrigation agriculture and horticulture both more likely and more profitable; and (3) dried, salted, and smoked fish, various types of fowl, reeds, and other marsh or littoral resources preferentially produced by polities near the Persian Gulf.

A second stage in the process may have started already by the middle of the fourth millennium (Middle Uruk period), and would have been marked by an emerging elite awareness of the social implications of the intraregional trade patterns in place until that point in time. In this stage, processes of competitive emulation would expedite the diffusion of technologies and practices that were initially developed by individual alluvial centers exploiting specialized niches but soon came to be perceived as highly advantageous by many of the centers in competition. This naturally would have decreased the level of regional specialization within the alluvium as each competing polity used the material surpluses and human skills acquired during the earlier stage to replace some imports from nearby centers, or possibly even from foreign areas, by creating their own productive capacities for those products, thus setting in motion the further growth spurt that accrues from the import-substitution mechanism discussed earlier.

The third stage of the process, datable to the second half of the fourth millennium (Middle and Late Uruk periods) would have been characterized by heightened competition between alluvial polities that had by now achieved broadly comparable productive capabilities. Since such polities no longer had much to offer each other in terms of exchange, I would expect this stage to include a significant expansion of external trade between individual alluvial cities and neighboring areas. Accordingly, ongoing import substitution processes in the south at this stage

should have begun to focus primarily on the replacement of foreign commodities.

Enhanced foreign trade in this third stage would have been made possible by two interrelated factors, which can be thought of as necessary conditions for the Sumerian takeoff. The first was the early development and diffusion across the south of industries that were originally intended to satisfy local consumption requirements but which were easily adapted for export markets outside of the alluvium in later phases—a clear instance of “exaptation” in social evolutionary processes.1 No doubt woolen textiles were the principal commodities fulfilling this double role in the fourth millennium, as they were later on in the historic periods. However, other indigenous southern industries that could be adapted for export at this time included animal hides, dried fruit, salted or smoked fish, and a variety of processed pastoral (animal and dairy fats) and agricultural (honey? unguents? aromatic oils? wine) products that likely constituted the contents of the various types of Uruk ceramic vessels (four-lugged, spouted, and pear-shaped jars) often found in indigenous Late Chalcolithic sites across the Mesopotamian periphery (Algaze 1993 [2005a],

63–74; Englund 1998, 161–69).2

The second factor was the domestication of the donkey sometime by the middle of the fourth millennium (H. Wright 2001, 127). This had interrelated conceptual and material consequences. Starting with the conceptual, the use of donkeys must have provided southern Mesopotamian polities with the enhanced geographical and “ethnographic” knowledge (Helms 1988) of neighboring regions and societies and of the resources available therein that are always a necessary precondition for the success of sustained efforts of cross-cultural trade and expansion. In studying the orientation of trade relations between different groups, economic geographers correctly observe that, historically, the trade of any polity expands (or contracts) in direct relationship with the limits of commercial intelligence available to its merchants and institutions (Vance 1970, 156). Such limits were substantially expanded by the use of donkeys in the Uruk period for overland travel.

Equally important would have been the material consequences of the introduction of domestic donkeys for southern polities: for the first time in their history they could export alluvial goods in bulk to foreign regions, something that was not practicable before, when all exports beyond the alluvial delta would have had to be carried on the backs of men. It is possible to use existing ethnographic and historic data for the ef-

ficiency of human versus donkey portage in traditional societies to assess the economic impact that the introduction of pack animals may have had on early Sumerian economies, and the opportunities for growth (via export) that would have been created by that introduction. Available data show that the relative efficiency of the two modes of transport varies greatly in different cultures and areas of the world, but equalized for time and distance, at a minimum, donkeys can carry at least twice the amount of cargo that humans can, and in many cases substantially more.3 These numbers appear to hold when we narrow our focus to ancient Mesopotamia. The same Old Assyrian data noted above in connection with the capabilities of donkey caravans indicate that individual porters could carry standard loads of up to 30 kilograms (Dercksen 1996, 61–63), while, as will be remembered, donkeys could carry two and a half times this amount, up to 75 kilograms’ worth of goods. We have no data for the average distance that porters could cover in one day.

The Old Assyrian evidence can also be used to obtain a rough idea of the scale of the export activities that would have become possible in southern societies as a result of the introduction of pack animals. While most Old Assyrian caravan loads usually consisted of a combination of metal (tin) and textiles, occasionally loads comprising only textiles are attested. These are immediately pertinent to the Uruk case, since, as noted above, finished textiles would likely have been one of the primary commodities exported from the alluvium at the time. When carrying only textiles, Old Assyrian donkeys were each packed with 20 to 30 bundles of cloth (depending on quality and weight). As noted earlier, most caravans consisted of about 2 animals. However, larger individual caravans of up to 5, 9, 14, and, in one case, 18 animals carrying solely or primarily textiles are also known (Larsen 1967, 146; Veenhof 1972, 69–76). Presuming that the capabilities of the donkey breeds available in the fourth millennium would have been similar to those available to Old Assyrian traders,4 and, further, that caravan procedures in the two periods would also have been similar, the Old Assyrian data suggest that the domestication of the donkey opened the door for individual alluvial producers to export to distant consumers anywhere between 150 and 1350 kg of finished textiles per shipment (i.e., between 40–60 to 360–540 individual bundles of cloth).

In the final analysis, however, the economic impact on early Sumerian economies of the domestication of the donkey cannot be reduced to statistics. While human porters were used in ancient Mesopotamia to carry