This article briefly presents and discusses some problems, theoretical questions and methodologies relating to the author’s PhD research, currently being developed at the FCSH/NOVA and at the École nationale des chartes. The main objective of this research is to study the archive of the viscounts of Vila Nova de Cerveira and marquises of Ponte de Lima, analyzing the social and the institutional history of the families that produced it between the fourteenth and the seventeenth century (when their house became consolidated). The aim is to determine the “sociogenetic” role of the archive for these family groups and for this house. With this in mind, an in-depth analysis of this archive is being carried out fi rstly as an attempt to reconstruct the informational production of the families that were both at the origin of the house of the viscounts and that later came to integrate it, and secondly to determine how that information was transformed into documents and into archive(s) throughout this period. This approach assesses new ways of archive research as infl uenced by the tournant documentaire, the archival turn, and the documentary history of institutions. Consequently, it tests the recent confl uence of theories and methodologies in History and Archival Science/Information Science for the analysis of archives, which have become known collectively as the social history of archives and information, and, in Portugal, as Historical Archivistics.