It is well known that there was an increasing concern with clothing as a means of social and cultural distinction in the late medieval and early modern periods. This has been called the birth of fashion. One way in which this importance was expressed was through the development of some well-defined sartorial codes and rules, both tacit and explicit. These gradually lead to more exhaustive and specific regulatory forms. Hitherto, most of the scholarly emphasis has been on the secular world, particularly through the study of sumptuary laws, whereas analysis of the ecclesiastical sphere (the Carmelite order apart) has not got much attention beyond anecdotal description. This dissertation aims to provide a 'thick description' to understand the meaning of ecclesiastical dress in a social and cultural context for the period 1215-1650. Thus, the focus is not on clothes as such, but on the ways by which dress can express conscious and unconscious ideas at the base of the interaction between people, groups and institutions. Studying the dynamics, ideas, worries and controversies generated by religious habits, both within and outside the religious orders, reveals the layers of meaning that exist beyond the anecdotal evidence. And what they reveal is how religious orders in Western Europe developed a complex process of identity formation in which clothing, in its different levels, played a fundamental role. What lies at the core of this analysis of the conceptions about religious clothing – used as a heuristic tool – is precisely its capacity to show not only how the identities of the religious orders of the period evolved, but also how they were perceived and conceived, and how they shaped these changes