A letter of marque and reprisal () was a government license in the Age of Sail that authorized a private person, known as a privateer or corsair, to attack and capture vessels of a nation at war with the issuer. Once captured, the privateers could bring the case of that prize before their own admiralty court for condemnation and transfer of ownership to the privateer. A letter of marque and reprisal would include permission to cross an international border to conduct a reprisal (take some action against an attack or injury) and was authorized by an issuing jurisdiction to conduct reprisal operations outside its borders. Popular among Europeans from the late Middle Ages up to the 19th century, cruising for enemy prizes with a letter of marque was considered an honorable calling that combined patriotism and profit. Such privateering contrasted with individuals conducting unlicensed attacks and captures of random ships, which was known as piracy; piracy was almost universally reviled. In practice, the differences between privateers and pirates were often at best
Una carta de marca y represalia () fue una licencia gubernamental en la Era de la Navegación que autorizó a una persona privada, conocida como privatista o corsair, para atacar y capturar buques de una nación en guerra con el emisor. Una vez capturados, los privatistas podían llevar el caso de ese premio ante su propio tribunal de almirantazgo para la condena y transferencia de propiedad al privado. Una carta de marca y represalia incluiría el permiso para cruzar una frontera internacional para llevar a cabo una represalia (tomar alguna acción contra un ataque o lesión) y fue autorizado por una jurisdicción emisora para llevar a cabo operaciones de represalia fuera de sus fronteras. Popular entre los europeos desde la Edad Media hasta el siglo XIX, cruzar por premios enemigos con una carta de marca se consideraba una llamada honorable que combinaba patriotismo y beneficio.