As far back as the Middle Ages, private ship captains were authorised by governments to harry enemy merchant shipping. Their ships, and their operators, came to be called ‘privateers’. The letters of marque and reprisal that gave privateering ship captains permission to strike enemy vessels had appeared in English law by the 1300s.
The earliest usage of privateer in reference to a privately owned, armed vessel, or possibly to individuals engaged in privateering, came in 1664, by one Colonel Lynch, the Provost Marshall for Jamaica. ‘The calling in of privateers,’ he wrote, ‘will be but a remote and hazardous expedient.’
Later, in the 1748 account of the global circumnavigation conducted by the Royal Navy’s Commodore George Anson, A Voyage Round the World in the Years 1740-4, Anson noted that ‘men-of-war [warships] are much better provided with all conveniences than privateers.’
Licensing privateers (effectively legalising piracy) was an inexpensive way for a government, especially one with a weak navy, to boost its naval power. During the American War of Independence, letters of marque and reprisal were issued by the United States Continental Congress, as well as by state governments.
A captured ship and its cargo would be sold, and the prize money garnered would be shared between the privateering ship’s owner, its captain, the crewmen, and the licensing government.
American privateers again proved troublesome for Britain in the War of 1812. The Duke of Wellington, in an 1813 dispatch to Earl Bathurst, wrote of an ‘account of the consequences of the capture of a Mediterranean packet [a mail-carrying boat] by an American privateer.’
The abolition of privateering was declared at the Paris Conference of 1856 by several Western nations. The United States did not agree to the ban on the grounds that the practice might still be required. Eventually, however, it too outlawed privateering.