Most Roman cities survived into the early Middle Ages as political and economic centres. (The majority of those that failed were in the Apennines and, to a lesser extent, on the coast.) Their function as political centres has already been discussed; there is more dispute about their economic role, however. They must certainly have looked dilapidated, with their Roman monumental structures serving as quarries for rebuilding elsewhere; early medieval public buildings were, as noted, smaller and also probably fewer in number—the cathedral and the local royal palace being the most important ones by far. Archaeologists in cities such as Brescia or Verona have found a much less dense settlement network inside the walls of the early medieval cities than in the preceding or later ones, with lower buildings, more courtyards, many more open spaces used for agriculture, and, often, a trend toward building in wood. But both of these cities and several others still followed Roman street plans. It is likely that many cities maintained an urban economic identity, with some commercial and artisanal specialization (at least in luxury goods). Lucca’s documents in the 8th century show, among others, gold workers, cauldron makers, physicians, and builders, and such figures also appear in texts for Milan and other cities in the 9th century. Essentially, this kind of artisanal activity relied on the city’s role as the residence not only of bishops, dukes, counts, and administrative officials but also of a high proportion of the local aristocracy. The local political interests of the latter can be seen in a wave of competitive church building in the 8th and early 9th centuries; dozens of (probably very small) churches existed in each major centre by 900.

Commerce was undoubtedly far weaker in the early Middle Ages than under the Roman Empire. Archaeology shows it very clearly: the large number of African amphorae and fine ceramics found on every late Roman site in peninsular Italy decreases sharply in the 5th century, and these artifacts vanish in the 6th century. Only from the 8th century onward is there evidence again of pottery-exchange networks, but exclusively on the level of the city territory and, as far as is yet known, only around some cities—notably Rome, which remained the largest city in Italy, though it was only a fraction of its former size. City-country exchange networks were probably relatively weak in the 7th and 8th centuries, although they never altogether disappeared. From the 9th century onward, however, consistent documentary evidence of urban markets shows that these networks were developing again.

Most Classical cities had not been major centres of international commerce, or, at least, such commerce was less important as a reason for their existence than the fact that major landowners lived in them. The sharp decline of this commerce in the early Middle Ages was thus not in itself a threat to city life. But its slow revival from about 750 onward did help these cities, for they were still at the nodes of surviving Roman river and road networks that, with few changes, were to become the commercial routes of the High Middle Ages.

In the early 8th century King Liutprand issued a text that regulated the salt trade from the Venetian lagoon up the Po River. In the following century this trade developed and increasingly came into the hands of local rather than Venetian merchants. Cremona, among other cities, had become a major mercantile centre by the late 10th century, and not, by then, only for salt; the Venetians, on their way to Pavia, brought—among other wares—spices, ivory, and Byzantine cloth. Venice itself was the focus of this international trade by the 9th century; the will of its duke Giustiniano Parteciaco (also spelled Partecipazio), dating from 829, includes the first reference in medieval history to capital investment, in ships and their goods. By the end of the 10th century the Venetians dominated the trade of the Adriatic Sea and controlled much of its eastern coast.

Inland, however, the spread of both international and local commerce was bringing a new and visible prosperity by the 10th century to many cities, including Cremona, Pavia—the old political capital still automatically visited by many traders from Venice—the southern cities, and, above all, Milan, which was fast becoming the major economic centre of the Italian kingdom. The northern Italian trade routes, along the Adriatic coast, up the Po River, and across the Alps, were coming to rival the older routes around the western coast of Italy, via Amalfi and Gaeta (or, later, Pisa and Genoa) and up the Rhône River. Both routes were to develop dramatically in the following centuries. But they did not in themselves create urban life in Italy; that was done by the local aristocracy. The continuing domination of Italian cities by landed aristocrats was to condition much of their future history.