Asiento

In the history of slavery, asiento (or assiento, meaning "assent") refers to the permission given by the Spanish government to other countries to sell slaves to the Spanish colonies, from the years 1543–1834.
*"Asiento" in Spanish means "agreement"; the term is common in Spanish juridical terminology.

Through an asiento, a trade relationship was established whereby a set of traders was given a monopoly over that route and/or product. In this case, it refers specifically to a monopoly over the trade of slaves between Africa and the Americas. According to the "Encyclopædia Britannica", this asiento existed between the early 16th and mid 18th century.

Initially, Portugal dominated the slave trade. Before the onset of the official asiento in 1595, the Spanish fiscal authorities gave individual asientos to merchants, primarily from Portugal, to bring slaves to the Americas. For the 1560s most of these slaves were obtained in the Upper Guinea regions, especially in the Sierra Leone region where there were many wars associated with the Mane invasions. However, following the establishment of the Portuguese colony of Angola in 1575, and the gradual replacement of Sao Tome by Brazil as the primary producers of sugar, Angolan interests came to dominate the trade, and it was Portuguese financiers and merchants who obtained the larger scale, comprehensive asiento that was established in 1595. Angolan dominance of the trade was pronounced after 1615 when the governors of Angola, starting with Bento Banha Cardoso, made alliance with Imbangala mercenaries to wreak havoc on the local African powers. Many of these governors also held the contract of Angola as well as the asiento, thus insuring their interests. Shipping registers from Vera Cruz and Cartagena show that as many as 85% of the slaves arriving in Spanish ports were from Angola, brought by Portuguese ships. The earlier asiento period came to an end in 1640 when Portugal revolted against Spain, though even then the Portuguese continued to supply Spanish colonies. In the 1650s Spain sought to enter the slave trade directly, sending ships to Angola to purchase slaves and toying with the idea of a military alliance with Kongo, the powerful African kingdom north of Angola. But these ideas were abandoned and the Spanish returned to Portuguese and then Dutch interests to supply slaves. Later in history, Britain and Holland dominated the slave trade. The slaves were sent mostly to the New World colonies.

At the conclusion of the War of the Spanish Succession, the Treaty of Utrecht gave to Great Britain a thirty-year "asiento", or contract, to furnish (supply) an unlimited number of slaves to the Spanish colonies, and 500 tons of goods per year. This provided British traders and smugglers potential inroads into the traditionally closed Spanish markets in America. Disputes connected with it led to the War of Jenkins' Ear (1739).

The reason for such patents is that trade routes were not what we take for granted today. At the time, the development of ports on either side and facilities for the trade was very expensive to develop and more so to manage. The European governments found it easier and more lucrative to assign a monopoly (ostensibly protected by the armada) to a group of traders who would pay the government for the privilege and invest in the infrastructure to enable the trade. One must remember that these were pre-bureaucratic and fractured governments. Organization and leadership of distant activities was often placed in the hands of traders who would pay a flat fee. For the government, the sole purpose of these endeavours was money. The spread of Christianity should not be forgotten as a motivator, but this was always secondary to resources (gold, spices, etc.). There are many examples of Isabella referring to the Christianizing of the "heathens" but even she wouldn't have the resources for this if there weren't gold to pay for it. This is why Florida never gained significant development until much later. However it is a more modern concept that land had value above and beyond the resource extraction that could be gained by controlling it. So really, it is dangerous to look at the asiento or patent system as different from how we currently look at patents on drugs or technology. The government, in order to facilitate the development of such things, literally sells the right to them to gain rent from the exclusion of others.

Similar patents in the English system were the Virginia Company, the Levant Company, and the Merchant Adventurers' patent of trade with the United Provinces (pretty much concurrent with modern day Netherlands). A detailed and well written overview of the English system is given by Robert Brenner in "Merchants and Revolution".

(See also: Chartered companies)