From the thirteenth century, maritime commerce crossed borders and inaugurated a network of routes, from Scandinavian port towns to Castile and Mediterranean markets; a network of seaways giving rise to the consolidation of an increasingly prosperous and fluent mercantile traffic. Medieval maritime commerce was governed by consuetudinary uses and customs of mariners, transporters and carriers; it later became necessary to commit these norms to writing as a means of facilitating their dissemination and enforcement, providing security to mercantile traffic, offering assurance for merchants and seamen and expediting the resolution of conflicts.

Thus, a set of legal corpora – ius privatista – was developed and disseminated along the Atlantic waterfront, systematising maritime transport services, with the main aim of preserving the cargo, since ‘the ship is its cargo’. Areas covered include the loading, type and form of stowage, protection during the voyage and the unloading, storage and, if necessary, the transhipment of merchandise.

A task as complex as that of cargo handling drove the adaptation of port compounds through the building of infrastructures to facilitate tasks and incorporate specialised technology for the handling of cargo that on occasions was weighty and voluminous. Hence, a long chain of players participated in maritime transport, men of the sea and men of the land, the latter being the final actors in the loading and unloading of merchandise.