The following study deals with a period of rapid urban growth in the Latin Mediterranean. A long-standing interest in the sophisticated environment created by the expanding towns of medieval Europe first drew my attention to the topic, and the partially exploited wealth of Catalonian archives enticed me to undertake an examination of Barcelona. Both the subject and the location have revealed new and unexpected perspectives to me over the decade in which this work has matured. From the perspective of urban studies on the medieval Mediterranean, it quickly became clear that many of the models of early urban development and social organization I had been prepared to employ failed to capture the nature of the world that slowly opened up before me as archivists dutifully carried out stacks of parchments and thick notarial registers. On my first day of investigation in the splendid viceregnal palace that houses the Arxiu de la Corona d'Aragó, the better part of an afternoon was spent (with occasional breaks to observe with romantic fascination the guitarist playing Albéniz outside and avid youngsters intent at soccer in the ancient Plaça del Rei) struggling over the cramped hand of a royal scribe, who must have intended to confound the uninitiated with inexplicable strokes and indecipherable contractions. One document, however, held my attention. It contained a splendid account of an urban feud, full of intimidation, insults, bloodshed, and simmering hatred; in short, just what a generation of studies of Italian towns had taught me to expect. Relieved, I seemed to have stumbled onto a promised land of social conflict.