Letters of marque

A letter of marque and reprisal was a government license issued during the Age of Sail. It allowed a private individual—called a privateer or corsair—to attack and seize ships belonging to a foreign nation at war with the issuing government. The license authorized international military operations against a specific enemy as a form of retaliation for a prior attack or injury. Any captured vessels, known as prizes, had to be brought before the government's admiralty court, which would decide whether to condemn them and transfer ownership to the privateer. This practice was common among Europeans from the late Middle Ages through the 19th century. Cruising for enemy prizes under a letter of marque was seen as an honorable pursuit, blending patriotism with profit. Such legally sanctioned privateering stood in contrast to the unlicensed seizure of random ships, which was called piracy and universally condemned. In reality, the line between privateers and pirates could be thin, sometimes just a matter of interpretation.

The terms "letter of marque" and "privateer" were occasionally used to describe the ships themselves that operated under these licenses. In that context, a letter of marque referred to a slow, square-rigged cargo vessel that might capture a prize if the chance arose during its normal trading. Meanwhile, "privateer" typically meant a fast, fore-and-aft rigged fighting ship built for speed and weatherliness. Letters of marque let governments wage war using mercenary private captains and sailors instead of their own navies, saving time and money. Rather than building and maintaining a navy during peacetime, governments would wait until war broke out to issue letters of marque to privateers, who financed their own ships in hopes of prize money.

The word "marque" comes from the Old English *mearc*, from the Germanic *mark-*, meaning boundary or boundary marker, which traces back to the Proto-Indo-European root *merǵ-*, also meaning boundary or border. The French *marque* comes from the Provençal *marca*, from *marcar* (also Provençal), meaning to seize as a pledge. According to the Oxford English Dictionary, the first recorded use of "letters of marque and reprisal" was in an English statute in 1354 under King Edward III. The phrase referred to a license granted by a sovereign to a subject, authorizing him to make reprisals against the subjects of a hostile state for injuries allegedly done by the enemy's army.

During the Middle Ages, armed private vessels with their sovereign's tacit consent—though not always an explicit commission—regularly raided the shipping of other states. For example, the Englishman Sir Francis Drake attacked Spanish shipping, and Queen Elizabeth I, despite claiming innocence, took a share of the prizes. The Dutch jurist Hugo Grotius's 1604 work *De Iure Praedae* (Of The Law of Prize and Booty) was a legal brief defending Dutch raids on Spanish and Portuguese shipping. King Henry III of England issued what later became known as privateering commissions in 1243. These early licenses were granted to specific individuals to seize the King's enemies at sea, with the proceeds split between the privateers and the Crown. The letter of marque and reprisal itself was documented in 1295, fifty years after those wartime privateer licenses first appeared. According to Grotius, letters of marque and reprisal were akin to a "private war"—a concept foreign to modern thinking but fitting an age when the ocean was lawless and all merchant ships sailed armed for self-defense. A reprisal involved seeking the sovereign's permission to exact private retribution against a foreign prince or subject. The earliest recorded instance of a licensed reprisal in England was in 1295 under King Edward I. The idea of reprisal, and the notion that just war involved avenging a wrong, was tied to the letter of marque in England until 1620. To apply for such a letter, a shipowner had to submit an estimate of actual losses to the Admiralty Court.

Licensing privateers during wartime became widespread in Europe by the 16th century, when most countries began enacting laws to regulate the granting of letters of marque and reprisal. This business could be very profitable. During the eight years of the American Revolutionary War, ships from the tiny island of Guernsey carrying letters of marque captured French and American vessels worth £900,000 (equivalent to about £125,702,134 in 2025). Guernsey privateers continued operating during the Napoleonic Wars. Although privateering commissions and letters of marque were originally distinct legal concepts, these differences became purely technical by the 18th century. For instance, Article I of the United States Constitution says, "The Congress shall have Power To ... grant Letters of marque and reprisal ..." without separately mentioning privateer commissions. During the American War of Independence, the Napoleonic Wars, and the War of 1812, people commonly made a verbal distinction between privateers (also called private ships of war) and armed merchantmen, which were referred to as "letters of marque"—even though both received the same commission. The *Sir John Sherbrooke* (Halifax) was a privateer; the *Sir John Sherbrooke* (Saint John) was an armed merchantman. The East India Company arranged for letters of marque for its East Indiamen ships, such as the *Lord Nelson*. These ships did not need permission to carry cannons to defend against warships, privateers, and pirates on voyages to India and China, but the letters of marque ensured that if they had the chance to take a prize, they could do so without being guilty of piracy. Similarly, the *Earl of Mornington*, an East India Company packet ship of only six guns, also carried a letter of marque.