To build defenses, regulate and improve trade, raise taxes, and maintain order, organization of an urban area was necessary. The earliest attempts at united action of the burghers involved the forming of associations in which the burghers swore an oath binding themselves together in a personal bond of mutual support and defense. The communes grew in power and, as autonomous corporate entities, became extremely influential in organizing city government. By the late 12th cent., when cities were well established, all who chose to live in them had to take an oath acknowledging the authority of the communes.
Because the town was located on land belonging to a king or emperor (see feudalism), the town owed allegiance to its lord and paid him tribute and, in wartime, service or money payment. Suzerains often favored the communes as sources of wealth and confirmed their rights in liberal charters. Disputes, nevertheless, frequently arose between communes and their overlords. In the struggle between kings and nobles, the kings usually strengthened the communes and sought alliances with them. However, in the 16th and 17th cent., when European states (notably France and Spain) became centralized, the privileges of the communes were gradually withdrawn.
The extent of their liberties and the details of their organization varied widely. A common feature was the elected council. The magistrates were usually called consoli, podestàs, and capitouls in Italy and S France, échevins and jurés in N France and the Low Countries, Senatoren and Ratsherren in Germany. Corporations and guilds gained a prominent share in the government. Militia insured the defense.
The earliest communes arose in N and central Italy. In the struggle between emperors and popes, the communes forming the Lombard League gained a great deal of independence and became almost synonymous with the cities themselves. In the 14th cent., however, the communes were usurped by local tyrants. The commune of Rome was established by Arnold of Brescia in 1144. In the Low Countries, e.g., in Flanders, communes arose very early and enjoyed very wide privileges. In S France, Avignon, Arles, and Toulouse were outstanding examples of self-governed communes, as Barcelona was in Spain. In Germany, cities such as Frankfurt, Cologne, Nuremberg, Augsburg, and Lübeck became republics immediately subject to the emperor (imperial and free imperial cities). Others, such as Magdeburg, held charters that became models for numerous towns in N Germany, Bohemia, and Moravia.
See W. F. T. Butler, The Lombard Communes (1906, repr. 1969); H. Pirenne, Medieval Cities (tr. 1925, repr. 1969); M. V. Clarke, The Medieval City State (1926, repr. 1966); J. H. Mundy and P. Riesenberg, The Medieval Town (1959).