Letter of marque in the context of "French corsairs"

A declaration of war is a formal act by which one state announces existing or impending war activity against another. The declaration is a performative speech act (or the public signing of a document) by an authorized party of a national government, in order to create a state of war between two or more states.

The legality of who is competent to declare war varies between nations and forms of government. In many nations, that power is given to the head of state or sovereign. In other cases, something short of a full declaration of war, such as a letter of marque or a covert operation, may authorise war-like acts by privateers or mercenaries. The official international protocol for declaring war was defined in the Hague Convention (III) of 1907 on the Opening of Hostilities.

A privateer is a private person or vessel which engages in commerce raiding under a commission of war. Since robbery under arms was a common aspect of seaborne trade, until the early 19th century all merchant ships carried arms. A sovereign or delegated authority issued commissions, also referred to as letters of marque, during wartime. The commission empowered the holder to carry on all forms of hostility permissible at sea by the usages of war. This included attacking foreign vessels and taking them as prizes and taking crews prisoner for exchange. Captured ships were subject to condemnation and sale under prize law, with the proceeds divided by percentage between the privateer's sponsors, shipowners, captains and crew. A percentage share usually went to the issuer of the commission (i.e. the sovereign). Most colonial powers, as well as other countries, engaged in privateering.

Privateering allowed sovereigns to augment their naval forces at relatively low cost by mobilizing privately owned armed ships and sailors to supplement state power. For participants, privateering provided the potential for a greater income and profit than obtainable as a merchant seafarer or fisher while avoiding the dangers associated with outright piracy. However, the line between privateers and pirates was not always clear.

Piracy is an act of robbery or criminal violence by ship or boat-borne attackers upon another ship or a coastal area, typically with the goal of stealing cargo and valuable goods, or taking hostages. Those who conduct acts of piracy are called pirates, and vessels used for piracy are called pirate ships. The earliest documented instances of piracy were in the 14th century BC, when the Sea Peoples, a group of ocean raiders, attacked the ships of the Aegean and Mediterranean civilisations. Narrow channels which funnel shipping into predictable routes have long created opportunities for piracy, as well as for privateering and commerce raiding.

Historic examples of such areas include the waters of Gibraltar, the Strait of Malacca, Madagascar, the Gulf of Aden, and the English Channel, whose geographic structures facilitated pirate attacks. The term piracy generally refers to maritime piracy, although the term has been generalized to refer to acts committed on land, in the air, on computer networks, and (in science fiction) outer space. Piracy usually excludes crimes committed by the perpetrator on their own vessel (e.g. theft), as well as privateering, which implies authorization by a state government.

Robert Surcouf (French pronunciation: [ʁɔbɛʁ syʁkuf]; 12 December 1773 – 8 July 1827) was a French privateer, businessman and slave trader who operated in the Indian Ocean from 1789 to 1808 during the French Revolutionary and Napoleonic Wars. Capturing over 40 prizes, he later amassed a large fortune from a variety of commercial activities, such as ship-owning, privateering, slave trading and owning land.

Surcouf started his maritime career as an officer on the ships Aurore, Courrier d'Afrique and Navigateur. Having risen to the rank of captain, he illegally engaged in slave trading onboard the slave ship Créole. Surcouf then captained the merchantman Émilie, on which he engaged in commerce raiding despite lacking a letter of marque. He preyed on British shipping, capturing several merchantmen including the East Indiaman Triton, before returning to the Isle de France where his prizes were confiscated. Surcouf then returned to France, where he obtained prize money from the government. Returning to the Indian Ocean, Surcouf captained the privateers Clarisse and Confiance, raiding British, American, and Portuguese shipping. He captured the East Indiaman Kent on 7 October 1800. Returning to France, Surcouf was awarded the Legion of Honour and settled down as a businessman.