During the Norman period the growth of the urban areas was modest, in no way comparable to what was going on in northern Italy. This was due, above all, to the fact that the Norman lords preferred to reside in rural castles. This meant that, with regard to both their structure and their administrative forms, towns were often no different from large villages. Also from a legislative standpoint, the Norman domination - with rare exceptions - did not allow the cities to have a significant form of autonomy. One of the most outstanding features of the major cities (Naples, Bari, Salerno, Palermo and Messina) was probably the presence of numerous communities of foreigners that vitalised them, especially from a mercantile point of view.
In the Middle Ages, the term ‘city’ was usually applied to towns with a cathedral. However, in southern Italy the conditions in which the network of bishoprics was formed created an ambiguous situation: on the one hand, small towns, such as Teramo, were the centres of dioceses, on the other, true cities were without a bishop (Barletta, Foggia, etc.). The largest cities in the Norman period were those already existing in antiquity, such as Naples and Palermo, then the Lombard and Byzantine capitals: Salerno, Capua, Benevento and Bari. Otherwise there were only minor urban areas that never grew into anything much more than villages. This was the case not only with Robert Guiscard’s capital at Melfi but also Gaeta and Amalfi, which, for a long period, were independent states. The existence of walls was not in itself a distinguishing feature of urbanisation because they were often found in the rural castra (fortified village). In the 12th century, many cities expanded and suburbs were constructed
In the course of time the cities of southern Italy, the control of which became increasingly rigorous, lost - with a few rare exceptions - any administrative originality. One of the principal causes of this development - which was not, however, linear - was the weakness of the bishopric. In Byzantine Apulia, there was a strong tendency towards self-government, especially in the case of Bari; many Apulian cities negotiated independently with the Norman leaders without the backing of the imperial authorities. In Muslim Sicily the disintegration of the power of the Kalbite dynasty allowed some cities to become virtually independent, as also happened with the duchies on the Tyrrhenian coast of the mainland (Gaeta, Naples and Amalfi). There were independent political movements in Benevento; then, at the end of the 11th century, it accepted papal lordship.
In the first place, the Norman conquest tended to favour, in contrast to the pre-existing political power, a certain degree of independence for the cities, for example Bari) but the institution of the monarchy led to the increasing subjection of the urban areas. It was only under King Tancred that, in the last years of the Norman kingdom, concessions were made with regard to independence, for example of Gaeta and Naples, but the model of the commune was only applied in the South in very limited circumstances
Social stratification in the Norman cities was very varied; in them, elements of a pre-feudal urban aristocracy survived. In Naples the patronymics pertaining to the upper levels of the urban society for centuries had crystallised; the same phenomenon existed in the Lombard cities (Benevento, Capua and Salerno) and in the Byzantine ones (Bari, Trani). At the end of the 12th century this urban upper class sometimes allied with elements of the feudal aristocracy. As far as Palermo was concerned, the complexity of the circles from which the palace personnel was chosen is well known.
Another development in the cities was a class of notables in which knights and those who were not coexisted; what they had in common was the fact that they possessed a certain patrimony, usually landed property, and held positions of responsibility in the feudal pyramid or the royal administrative hierarchy (the so-called baiulatio). The ports began to allow communities of foreigners, mainly merchants (Genoese, Venetians, Pisans), to establish themselves and - in contrast with the surrounding rural areas - the presence of a mercantile class was particularly important in them.
Unlike the other regions of Italy, in the Middle Ages southern Italy was characterised by a notable development of agriculture and a lack of the typically urban activities (industry, commerce), with the exception of maritime trade. This phenomenon was linked to the limited autonomy of the southern cities, especially in the Norman period. Nonetheless, the weakness of industry in southern Italy cannot only be explained in economic terms: the region was rich in raw materials (rock salt and sulphur in Sicily, iron and silver-lead in Calabria, sulphur in Sicily and Campania), and wood and stone were plentiful. The most flourishing sector seems to have been textiles, for which the raw materials were readily available. There was also a notable production of pottery and jewellery, both of which were greatly influenced by the techniques and styles introduced by the Byzantines and Arabs.
Little is known about the structure of industry in the cities of southern Italy during the Middle Ages, especially with regard to the organization of the different trades. It appears that in the 12th century they were, to a certain extent, distributed in certain areas : for instance, in Naples blacksmiths were concentrated in the quarter surrounding the church of San Pietro ad Ferrarios, and in Troia they seem to have founded a guild; in Amalfi there was a platea calzolariorum (shoemakers’ square). The social status of the craftsmen varied according to their trade. The most highly regarded were the metalworkers; the least esteemed were the textile and building workers. Some trades were marginalised: this was the case with dyeing, completely farmed out to the Jews and controlled by a monopoly under the authority of the cathedral. Other trades regulated for reasons of hygiene were the slaughtering of animals and the sale of meat. With a few rare exceptions - Naples, for example - the craftsmen’s products were never sold outside the area where they were produced, so the output was limited to local needs. In other words, there was a complete lack of trade over long distances.