The Roman empire was an urban empire. Where Rome found no cities it was obliged to create them, and where cities could not survive then neither could Rome. The city was the basic administrative unit where the ruling élite could compete for office, judge disputes and govern, where taxes could be determined and defences organized. Cities were also sacred places since the affairs of government needed divine guidance, and communities were bound together by city festivals organized in honour of the gods.
The economic role of the city was less important. Land was the principal source of wealth, whether in the form of rents or agricultural surplus and Classical cities never escaped the domination of the agricultural landowners. The self-governing city and its surrounding territory, although clearly defined one from the other, were administratively indivisible (Finley 1973). Long-distance trade in the ancient world was principally concerned with the small-scale transfer of luxury items and precious materials. Trade in less valuable goods remained severely limited by the prohibitive cost of transport, and local self-sufficiency was the norm.
The rapid growth of the Roman empire had an important effect on urban trade. The profits of conquest and empire were vast and unevenly spread, and the leading citizens of Rome became very rich indeed. This wealth was naturally invested in land, and large slave-run estates grew up in many parts of Italy. The demand for slaves was considerable and stimulated a major trade, paid for in part by the export of wine and oil. The profits of empire were also directed towards the competition for status in the towns; theatres, temples and baths were built to enhance the prestige of the leading houses and incidentally created work in the towns. Large towns with large appetites could grow, and urban trade became more necessary and more profitable (Hopkins 1978).
Two institutions of Rome, paid for by the profits of empire, had a major influence on the development of towns and trade in the Roman provinces. One of these, the grain supply of Rome, was effectively confined to the Mediterranean provinces but the other, the Roman army, was of enormous importance in the north-west. Soldiers in the frontier prov-