The collapse of the Roman Empire affected urban life even more profoundly than other aspects of society. Roman civilization had been distinguished by a high level of urban development, and the Germanic invasions of the late Roman period, by disrupting commerce and overthrowing the governmental structures that had once provided coinage, undermined two of the most crucial supports that made urban life possible. Cities were depopulated, sometimes to the extent of complete abandonment. Yet they never fully ceased to exist. Some major cities like Paris, Marseilles, Naples, and Rome itself remained in continuous occupation as urban centers, albeit in a decayed state, as did a number of lesser cities of the empire. Even at the time of the invasions, commerce never entirely dried up, and the barbarians themselves had learned the use of coin from their Roman neighbors. Urban life slowly reestablished itself over the course of the early Middle Ages. By 1200, cities and towns were numerous and prospering, and although the number of city dwellers was small in relation to the population at large—probably no more than 10 percent at any time in the Middle Ages—the towns wielded social and cultural influence well beyond their size.
No town in northern Europe better reflects the range of medieval urban activity than Paris. Already a substantial city in the Roman period, by the thirteenth century Paris had become a leading political, religious, cultural, and economic center, and arguably the most important city in Europe north of the Alps. Very little of medieval Paris survives after