Abstract

By the end of the Middle Ages, sea trade was essential for the economic development of the city of Oporto. At the time, its trade fleet had already established a number of international routes and its merchants were frequently present in several European ports. However, one of the most serious problems faced by this activity were the acts of piracy they were subject to from the English, French and Castilian. Based on a document of 1469, we are able to understand mercantile dynamics and, above all, the mechanisms employed by city authorities to protect its sea trade against the attacks perpetrated by these corsairs