ABSTRACT
It is likely that the basic need for food supply made grain the most important product of the ancient economy, and that the weight and bulk of grain made its transport over long distances by land prohibitively expensive except in times of dire shortage. The bulk of production in the ancient world was for local consumption. None the less, there is a mass of archaeological and literary evidence that the total of goods traded over long distances in the Early Roman Empire showed a marked increase over previous periods, and it is reasonable to view the empire as, to a limited extent, an economic unity, not least because it was subjected by the state to a coherent taxation system, and exchange was facilitated by the spread of Roman currency, or at least local currencies linked to Roman currency standards, throughout the empire.1
