There is not enough evidence to assert what conditions gave rise to the first cities. Some theorists have speculated on what they consider suitable pre-conditions and basic mechanisms that might have been important driving forces.
The conventional view holds that cities first formed after the Neolithic revolution. The Neolithic revolution brought agriculture, which made denser human populations possible, thereby supporting city development.
The advent of farming encouraged hunter-gatherers to abandon nomadic lifestyles and to settle near others who lived by agricultural production. The increased population density encouraged by farming and the increased output of food per unit of land created conditions that seem more suitable for city-like activities. In his book, Cities and Economic Development, Paul Bairoch takes up this position in his argument that agricultural activity appears necessary before true cities can form.