Scratch the Surface: Undisclosed Agency, Undisclosed Mandate, and the Mediterranean “Broth”

The doctrine of the undisclosed principal is commonly regarded as one of the most distinctive creations of the common law. This article questions that assumption by tracing the historical development of undisclosed agency and undisclosed mandate across the common law and civilian traditions. Taking inspiration from Olivier Moréteau's image of the Mediterranean as the "cauldron" of Western legal traditions, it argues that both English and Louisiana law emerged from a broader European mercantile tradition that predated the nineteenth-century codifications. The article examines the evolution of the English doctrine of the undisclosed principal alongside the law governing mandate and commission agents in France, Spain, Italy, and Louisiana. It shows that many of the solutions usually considered uniquely English—including the principal's priority over the agent's creditors and the possibility of holding an undisclosed principal liable—were already reflected in commercial practice, legal doctrine, and commercial legislation on the Continent. Rather than representing a unilateral common-law innovation later transplanted into Louisiana, the Louisiana rules on undisclosed mandate are better understood as part of a shared historical tradition rooted in the ius mercatorum and the practical needs of early modern commerce. By placing English and civilian sources within the same historical framework, the article challenges the conventional opposition between common-law undisclosed agency and civil-law mandate. It suggests that both are variations on a common legal theme shaped by transnational commercial practice before the rise of codification, strict privity, and the modern will theory of contract. In doing so, it illustrates Moréteau's broader insight that the deepest currents of legal development become visible only when one looks beneath the surface of doctrinal categories to uncover their shared genealogy.