Archives of commercial and industrial firms are not often used by the economic historians of the 14th-17th centuries, because they are scattered all over Europe, difficult to read and understand, especially when the archives are vast and scholars are working in isolation. The ENPrESa project, which gathers 19 researchers (of which 6 are graduate and post-doc students) supported by 4 research institutes, aims to study the Salviati Archives, which are preserved in the library of the Scuola Normale Superiore of Pisa. This huge collection, with thousands of ledgers and hundreds of bundles, ranging from the late 14th to the 17th century, is still underused, as it holds a huge amount of information, collected in dozens of complete series of account-books. The project will be organized in 5 different inquiries during its 3 years. The first step will be a preliminary survey of the archive, in order to spot the pertinent series and records, and to create a database of the entrepreneurs and other individual actors. One particular line of inquiry, which will primarily be made on the records of the Lyons companies, will address bookkeeping norms and exchange practice. Beyond the issue of accounting, the main problem will be the European dynamics of trade and monetary circulation, which will be observed specifically from the point of view of money exchange from the 14th century onwards. Mapping European trade from the Salviati books will be the aim of the 2nd inquiry. 3 test periods have been selected: — 1440-1460 (records of the London, Bruges, Lisbon, Pisa and Florence companies). — 1490-1510 and 1540-1560 (Lyons, Pisa, Florence, Antwerp, Naples, Venice). Textile produce will be the subject of a general exploration, which ranges from the problems of production (the archives preserve the records of more than 30 different craft companies) to those of commercialisation. The research will focus on silk and wool cloth production, golden thread spinning, and dyeing. The trade of Mediterranean and southern products (silk thread, sugar, leathers, carpets, feathers, dyeing stuff), as it results from the records of the Lisbon and Constantinople ledgers, will be the matter of a last inquiry. This research has many aims. First, a complete analysis of the archives, with inventories and calendars of the most notable documents: letters, memories, technological treatises, etc. The second result will be a comprehensive description of the Salviati family business network, with a prosopographic study of the actors, men and women, managers, shareholders, partners, wage earners, clients. Only an approach such as this makes it possible to understand how family firms work: a network with hierarchical organization, a collection of loosely linked companies, or firms with competing or cooperative overlapping ownerships. A major incentive for this program was the extraordinary opportunity of gathering scholars of different generations, all experts in research on medieval and early modern commercial records, as a team for a coherent inquiry about different topics in a unique archive. Of real relevance will be the participation of post-doc and graduate students, who will apply for the two post-doc positions, develop greater knowledge and skills, and obtain academic distinction. Moreover, in the present period when teaching and research in pre-industrial economic history is at stake everywhere in universities across the world, the results of this project as a way of training young scholars will be at least as important as the acquisition of knowledge.