According to available historical sources, risk protection for Portuguese sailors in the Middle Ages took less the form of the insurance than that of the pre-insurance. The latter was organised mostly around two institutions, namely the pooled resources of merchants (bolsas dos Mercadores) and various urban charitable associations known under the names of fraternities and hospitals for merchants and seamen. Though separately organised, through their goals and their relations both were involved in highlighting the role of urban oligarchies and their dealings with other powers established in the city.