Thank you for another highly informative article.

One criterion Childe's list suggests, but does not make explicit, is an area of cultural/political/administrative dominance that would include other settlements? Perhaps it could be (has been?) said that cities developed votively from within particular culturally homogenous geographical areas. City-states/empires could then be distinguished from cities by the existence of a sphere of dominance that had been imposed on a geographical area that extended beyond the original area within which the city had emerged? Just a thought, based on the notion of the broader geo-cultural significance of cities in 'civilization'.