Generally speaking, ancient civilizations gradually developed a more sophisticated economy following the creation of an agricultural surplus, population movement and urban growth, territorial expansion, technology innovation, taxation, the spread of coinage, and not insignificantly, the need to feed the great city centres and supply its huge armies wherever they might be on the campaign. The ancient economy displayed features of both underdevelopment and high achievement since it exhibited and an over-dependence on agriculture displayed a slow diffusion of technology and a high level of local town consumption rather than regional trade. Everything based on a low level of investment in industry, since it was mostly the slaves that were producing food. However, those rich enough to invest often overcame their scruples and employed slaves, freedmen, and agents to manage their business affairs and reap the often-vast rewards of commercial activity.
