Negotiatio and Taberna Instructa in Roman Law: between Dominium and Societas

This paper investigates the legal structure of negotiatio and taberna instructa in Roman commercial law, focusing on the relationship between dominium, societas, and business activity. The study aims to demonstrate that the negotiatio — understood as an ongoing commercial enterprise — cannot be reduced to the concept of dominium and possesses its own autonomous legal characterisation. The central hypothesis is that it is the negotiatio itself, and not ownership, that constitutes the unifying element of the taberna instructa and determines the legal effects of acts performed by the negotiator, whether a slave or a free person. The analysis employs a legal-historical and exegetical method, drawing on classical juristic sources and distinguishing between static and dynamic perspectives on the relevant institutions. The findings show that in the societas negotiationis, the legal framework governing contributions, acquisitions and liability is governed primarily by the structure of the negotiatio — not by ownership shares — and that the institution of praepositio provided the doctrinal vehicle through which jurists gave the business enterprise its own legal identity, a question that retains relevance for contemporary legal systems