A privateer was a private person or private warship authorized by a country’s government by letters of marque to attack foreign shipping. Privateers were only entitled by their state to attack and rob enemy vessels during wartime. Privateers were part of naval warfare of some nations from the 16th to the 19th century. The crew of a privateer might be treated as prisoners of war by the enemy country if captured. The costs of commissioning privateers was borne by investors hoping to gain a significant return from prize money earned from enemy merchants.
It has been argued that privateering was a less destructive and wasteful form of warfare, because the goal was to capture ships rather than to sink them.
The privateer was authorized by a national government to engage as a commerce raider, interrupting enemy trade. Privateers were of great benefit to a smaller naval power, or one facing an enemy dependent on trade: they disrupted commerce, and forced the enemy to deploy warships to protect merchant trade. Privateering was a way of mobilizing armed ships and sailors without spending public money or commissioning naval officers. Some privateers have been particularly influential in the annals of history. The captured cargo and the prize vessel itself, if serviceable, would be sold at auction with the proceeds distributed among the privateer’s owners, officers and crew; sometimes the vessels were commissioned into regular service as warships.