From the end of the Middle Ages onwards, sovereigns accorded private ship-owners the right to retaliate against ships from enemy countries. Moreover, these ship-owners would obtain official “letters of marque” which authorized them to capture or rob ships flying the flag of an enemy state- and in particular merchant vessels- in exchange for a portion of the proceeds. It was this legal and regulated action which distinguished them from pirates.
Commerce raiding emerged during the 14th century and peaked in the 17th century, under the reign of Louis XIV, before then experiencing a gradual decline in the 18th century and disappearing at the beginning of the 19th century. During its five centuries of existence, the majority of Breton ports harboured corsairs, with particularly strong traditions in Nantes (Jacques Cassard), Morlaix (the Coëtanlem at the end of the 15th century) and above all in Saint-Malo. Between 1688 and 1713, at the height of the phenomenon, Saint-Malo armed over 900 raiding ships.
Amongst the main Breton corsair figures, it is worth mentioning René Duguay-Trouin (1673-1736) and Robert Charles Surcouf (1773-1827). Duguay-Trouin distinguished himself in particular with the expedition that seized Rio in 1711 and captured many tons of gold. Surcouf asserted himself during the Revolution and the Empire, leading six large corsair expeditions during which he captured 47 ships, mainly British.
The targets changed according to the period: English and French at the end of the Middle Ages, Protestants during the Wars of religion, British in the 17th and 18th centuries…
Commerce raiding could be perceived as an alternative economic strategy for ship-owners and sailors who thus redirected their maritime activities that were heavily disrupted, indeed rendered impossible, by conflict. It had an essential economic role for ports such as Saint-Malo.