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 from researchers at Harvard University, the University of Cambridge, and the University of Edinburgh.
Published in the Aug. 31 issue of the journal Science, the research was led by Jason Ur, assistant professor of anthropology in the Faculty of Arts and Sciences (FAS) 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.
“The results of our work show that the existing models for the origins of ancient cities may in fact be flawed,” says Ur. “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.”
The outer city at Tell Brak. Broken pottery and other debris from the outer city is visible in the bottom of irrigation trenches. Today the former area of the outer city is entirely under agricultural fields and sheep pasturelands. 
