Letter of Marque

A letter of marque was a commission issued by a sovereign authorizing a private vessel to attack and capture enemy merchant shipping in wartime, turning a privately owned ship into a legal privateer. Holders posted bond, brought prizes before an admiralty court for condemnation, and shared the proceeds, distinguishing the practice from outright piracy. Widely used from the medieval period, the system was abolished among most maritime powers by the Declaration of Paris in 1856. The records of marque and prize are rich sources for maritime history.