Ancient city grew from outside in

Roughly 6,000 years ago, Mesopotamian cities in what’s now southern Iraq began as central clusters of buildings and then spread as orchestrated by authorities. About the same time, a different pattern of city development occurred in northern Mesopotamia, a new investigation finds. Instead of expanding outward from a densely populated core, an ancient metropolis in what’s now northeastern Syria emerged over an 800-year period as a number of settlements grew together and expanded inward toward what then became the city’s core, say Jason A. Ur of Harvard University and his colleagues.

Ur’s team studied the placement and age of pottery fragments and other artifacts on and around Tell Brak, a 40-meter-high, 1-kilometer-long earthen mound.

Outposts established by independent groups apparently merged as a result of their booming populations and gradual inward sprawl, creating a city with a central hub by about 6,000 years ago, the scientists report in the Aug. 31 Science. A contingent of all-powerful leaders did not plan Tell Brak’s urban transformation, as happened in southern Mesopotamian cities, the researchers propose.