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Bankers for the slave trade

Old documents provide evidence of the role played by prominent Lisbon merchants in the Angolan slave trade

Slavery’s ledger: on preceding page, an account for the purchase of slaves in Luanda

Torre do Tombo Slavery’s ledger: on preceding page, an account for the purchase of slaves in LuandaTorre do Tombo

In 1740, a Portuguese man named Domingos Dias da Silva was captain of a ship that transported textiles, sugarcane rum, wine and firearms to Luanda, the largest port linked to the slave trade in Angola, which was then a Portuguese colony. Silva sold his goods, received a portion of payment in the form of paper currency known as drafts (letras) or in bills of exchange (livranças) that functioned as promissory notes, and the other part in the form of slaves. After delivering the slaves to Brazil, he traded the bills for gold coins, filled the ship’s holds with sugar and returned to Lisbon, completing a trip that might have begun two years before. Silva earned enough money to participate in the slave contract auctions held by the Portuguese government and was able to offer more money than his competitors. After 25 years, he became a contractor, collecting taxes on behalf of the king on the slave business and accumulating wealth, power and prestige.

Silva’s trajectory sheds light on the complexities of the slave trade conducted among Portugal, Angola and Brazil, which historian Maximiliano Menz of the Federal University of São Paulo (Unifesp) is teasing apart using two sets of documents he found at the Torre do Tombo, one of Lisbon’s historical archives. The first set, consulted for the first time in 2011, consists of four books of export contracts for slaves purchased in Luanda between 1763 and 1770. At that time, an average of 9,000 Africans per year were being taken out of Angola as slaves. Over the course of three centuries, almost six million left–primarily from Angola–to work in the gold mines and sugar plantations of Brazil.

Written orders for payment, a type of paper currency commonly used in Angola

Ultramarino Historical Archive Written orders for payment, a type of paper currency commonly used in AngolaUltramarino Historical Archive

The second set of documents came to light during a second trip, in January 2015: it consists of almost 230 books – four per year, each containing 600 pages – which contain the records of goods passing through customs in Lisbon when being loaded on ships heading for Luanda between 1748 and 1807. In the 28 books he has already reviewed, Menz counted almost 2,000 entries with names of people and goods, and concluded that, although business was concentrated in the hands of important business owners like Da Silva, hundreds of people were participating , even priests, who could send wine to be traded for slaves in Luanda. “Yes, priests,” he says. “There was no problem with that. According to religious beliefs at the time, the slave trade provided a way of saving souls from damnation because the Africans were baptized before being put on ships bound for Brazil.”

Menz is using these documents to underscore the central role played by Portuguese contractors and export contracts in the creation of the credit and capital mechanisms associated with the slave trade. “The contractor functioned as a bank, lending money through bills of exchange issued in Luanda as a form of payment for the goods,” he says. “The papers were exchanged for money in Brazil when the slaves were sold.”

Menz is confirming an hypothesis advanced by historian Joseph Miller of the University of Virginia in the United States: “Miller proposes that, thanks to their control over slave contracts, traders in Lisbon monopolized the financing of the slave trade through the use of a series of privileges secured through those contracts and in this way, they provided the majority of goods that were used to purchase slaves in the interior of Angola.”

Panoramic view of Luanda in 1755, with the Sé, in the upper city (left) and the fort of São Miguel (right)

Guilherme Paes de Menezes / Wikimedia Panoramic view of Luanda in 1755, with the Sé, in the upper city (left) and the fort of São Miguel (right)Guilherme Paes de Menezes / Wikimedia

“At the time, Brazilian businessmen worked mostly in freight services, providing transportation for the human cargo that was to be sold in Brazil,” says Menz, who is suggesting an alternative vision to the one commonly held by historians, according to which Brazilian traders were the ones who controlled the slave trade. “This is the interpretation found in works by Luiz Felipe de Alencastro, Manolo Florentino, Roquinaldo Ferreira and Alexandre Vieira Ribeiro, but more recent research also recognizes the active involvement of mercantile communities in Lisbon and merchants in Luanda and Benguela, as argued by Gustavo Acioli Lopes, Jaime Rodrigues, Daniel Domingues Dias Silva, Mariana Cândido and the dissertation currently underway by Jesus Bohorquez.”

Meanwhile, further north, in the regions then known as Guiné and Mina, Europeans dropped anchor in the ports and simply purchased slaves who had already been captured by African traders, in Angola. Europeans were particularly intensely involved because Angola was a Portuguese colony. In the capital city of Luanda, the slave trade had become the main source of revenue for a population consisting of the Portuguese and the mestizos, who represented half of the city’s almost 5,000 inhabitants (the other half were slaves, some of whom awaiting the ships that would take them to the Americas).

The Portuguese financed the purchase of slaves in the Angolan interior by local merchants who were usually black or mulatto and so might default on the debt or die of malaria, yellow fever or other diseases common at the time. The biggest risk was the loss of slaves, who often perished on the voyage across the ocean to Brazil, which reduced profits. To mitigate this risk, the merchants preferred to receive payment in bills of exchange or drafts, exchanged in Brazil for gold or other products of the colony like sugar, cotton and tobacco, which were then sent to Lisbon.

The flow of credit worked until Domingos Dias da Silva, as a contractor, decided to change the rules: he stopped lending to other traders through bills of exchange, and forced them to purchase goods that he had sent from Lisbon. This strategy was unsuccessful because almost no one had cash to spend. Menz says that the governor of Angola, Francisco Inocêncio Coutinho, under pressure from merchants, wrote to Sebastião José de Carvalho e Melo, the Marquis of Pombal and Secretary of State of the Kingdom of Portugal. In 1770, to put an end to the confusion, Pombal cancelled the contracts and ordered that the taxes levied on the sale of slaves would be collected directly by the Royal Treasury. Despite these unexpected events, Silva apparently kept his business afloat and years later died a rich man. The slave trade was abolished in 1830, but in the years thereafter, many slaves were still being captured and sent illegally from Angola to Brazil.

An economic history of the slave trade in Angola: finance, taxation and transport (1703-1807) (nº 2014/14896-9); Grant mechanism: Regular Line of Research Project Award; Principal investigator: Maximiliano Mac Menz (Unifesp); Investment: ​R$37,344.11 (FAPESP).

Scientific article
MENZ, M. M. As geometrias do tráfico: o comércio metropolitano e o tráfico de escravos em Angola (1796-1807) Revista de História. Vol. 166, pp. 185-222. 2012.
MENZ, M. M. A Companhia de Pernambuco e Paraíba e o funcionamento do tráfico de escravos em Angola (1759-1775/80)Afro-Ásia. n. 48, p. 45-76. 2013