Ancient cities arose not by decree from a centralized political power, as was previously widely believed, but as the outgrowth of decisions made by smaller groups or individuals, according to a new study. Published in the Aug. 31st Science, the research was led by Jason Ur, assistant professor of anthropology in the Faculty of Arts and Sciences at Harvard University, with Philip Karsgaard of the University of Edinburgh, and Joan Oates of the McDonald Institute for Archaeological Research of the University of Cambridge. "Urbanism does not appear to have originated with a single, powerful ruler or political entity. Instead, it was the organic outgrowth of many groups coming together," says Ur.
     To understand patterns of population growth in the earliest urban areas, archaeologists surveyed the spatial distribution of artifacts at Tell Brak, a 40m-high, 1km-long archaeological mound located in northern Mesopotamia, in what is today northern Iraq and northeastern Syria. The researchers’ work was based on observation of surface objects at the site, along with satellite imagery and GIS spatial analysis. Surface artifacts included bits of broken pottery and other ancient garbage, which indicated to the archaeologists where the inhabitants of the city lived. In this survey, the patterns of distribution of these objects were examined over an 800 year period.
     While archaeologists had been aware of the large scale of Tell Brak, they had previously concentrated on excavating and observing the more densely populated 'central mound.' This field survey has demonstrated that the city was much larger geographically than realized, and had also been populated by settlement clusters surrounding the 'central mound.'
According to the survey of distribution of artifacts, around 4200 BCE the 'central mound' was suddenly surrounded by these clusters, suggesting immigration to the city. These clusters were separated from one another, indicating social distance among the groups, possibly because the social mechanisms that allow strangers to live together in an urban environment had not yet evolved.
     The theory of a singular leader as the catalyst for urbanization has been widely supported in part because it is reinforced by the story of Gilgamesh, who 'built' the city of Uruk. Uruk, located in what is today southern Iraq, had been considered the world's oldest city. The field survey, along with recent related excavation by the University of Cambridge has shown that the urban development of Tell Brak was concurrent, or may have been earlier, than the development of Uruk.
     An additional paper details the burials at Tell Majnuna, 0.5km from the main urban site at Tell Brak. Two mass burial pits have been excavated at this site. The first has so far revealed the bones of 34 young to middle-aged adults. Thus far, only a small portion have been excavated. "There could be hundreds and potentially thousands," said Augusta McMahon, an archaeologist at the University of Cambridge, UK. At least two skulls show signs of injuries that could have caused death. The absence of feet and hand bones and the fact that many of the skulls apparently rolled off when they were tossed in the pit hints that they were left to decompose before burial. A mass of pottery, mostly vessels for serving and eating, along with cow bones were also found lying on top of the skeletons. The experts interpret this as evidence for a large feast, according to the news report in Science.
     A second mass burial pit has been found about 12m away. At least 28 individuals have been uncovered from this location. Dr McMahon said she did not know whether the victors were defending or attacking Tell Brak. "We need at least another season to understand what happened," said Joan Oates, an archaeologist at Cambridge and project director at Tell Brak. She estimates that the Majnuna incident took place in about 3,800 BCE.

Sources: BBC News, EurekAlert! (30 August 2007)