Not nearly as famous as pirates, or as infamous as mercenaries, privateers have become a largely forgotten phenomenon of the pre-modern world. Of course, this is a debatable opinion, since most history students would agree that privateering constituted a major element of global trade and military conflicts for nearly 400 years.
Essential to understanding the concept itself is the difference between a privateer and a pirate. The more commonly known latter is an individual, performing maritime activities (usually raiding or plundering) outside state laws for personal gain. A privateer is closer to a mercenary in intent, they still perform activities considered illegal and to the loss of any state they target, but do so under a legal contract from their sponsor state.
Firstly, a privateer was required to obtain a “Letter of Marque” which authorized the captain of a ship to harass vessels of other nations with the implicit obligation to share some of the loot and profit with the state issuing that same authorization. Despite this effective contract, most privateers were largely independent, acting without any central command restricting their activities to certain areas and the ships of specific nations.
While there is some debate in the discourse, it is generally believed that the first privateers were privately owned ships equipped by coastal merchants to deal with growing issues of piracy. These were usually under contract to take solely ships suspected or convicted of piracy and filled a much-needed gap in naval protection in the years before regular navies.
The Anglo-Spanish War of 1585-1604 represents one of the first widely recorded instances of the deep connection between state conflict and private violence. Largely due to an inability to complete with a massive trading fleet amidst internal problems, Queen Elizabeth chose to allow the development of a private and mostly independent naval force. While it appeared to allow England to compete on the world theatre by simultaneously enlarging the nation’s profits while decreasing those of their main rivals, the success of this “supplementary navy” backfired as the Spanish saw little reason to not declare an official state of war.
Later in history, this pattern of employing privateers as a sort of privately funded surge for the state’s military and income became very prominent. After breaking the large Spanish monopoly on trade, the following English monarchs quickly reverted back to banning privateers (with notable exceptions). The other seafaring nations of the world however, having realized the potential of spreading the risks and costs of a navy to their wealthier and more entrepreneurial citizens, were quick to promote privateering.
During the Nine Years War, the French were swift in recognizing their lack of naval superiority and equally as swift in encouraging privateers, with England eventually losing about 4000 merchant vessels throughout the whole war. This war was closely followed by the War of Spanish succession where the English would lose over 3000 ships. By the middle of the 18th century however, repeated attempts at reforming naval doctrine to better protect merchant vessels and trade routes had paid off. The War of Austrian succession in 1740 saw the British navy inflicting heavier losses on their enemies than those suffered by their own merchant navy.
Privateering from that point onwards saw a steep decline, alongside an increased centralization of state navies and more widely recognized maritime treaties. The Paris Declaration Respecting Maritime Law of 1856, whose first major point was “Privateering is, and remains, abolished”, effectively marked the end of large state-sponsored privateering fleets. While privateering itself as a concept was still in use until the 1870 Franco-Prussian war, even then it had been subsumed as a subcategory of the regular navy, and no attempts to revive privateering were entertained by any major power since then.