The Beginnings of the Transatlantic Slave Trade

Before the Atlantic system

Slavery (owning people as property and forcing them to work) existed in many societies before 1450: in the Mediterranean and Europe, in the Islamic world, in African states, and in parts of the Americas. People were usually enslaved as war captives, as punishment, or for debt. Enslaved people were of every origin; in medieval Europe many came from Slavic lands (the root of the English word slave).

The transatlantic slave trade that began in this period became something new: it grew to an enormous scale; it was tied to plantation agriculture for world markets; enslavement became hereditary, passed from mothers to children for generations; and it became increasingly linked to race, with Europeans treating Black Africans as a people who could be enslaved.

The Portuguese beginning, 1440s to 1500

• In the 1440s, Portuguese ships began raiding and then trading for captives on the West African coast. The Portuguese chronicler Gomes Eanes de Zurara described captives landed at Lagos in Portugal in 1444. He wrote (paraphrased) that he pitied their suffering as families were separated, yet he justified it on the grounds that they would become Christians. His account shows how religion was used to justify enslavement even by people who saw its cruelty.
• Papal approval: the bulls ***Dum Diversas* (1452) and Romanus Pontifex (1455) authorized the king of Portugal to conquer non-Christian peoples and reduce them to perpetual servitude. Together with later documents, these ideas became part of what is called the Doctrine of Discovery. In 2023** the Vatican formally repudiated the Doctrine of Discovery, a step that First Nations, Métis and Inuit leaders in Canada had long called for.
• Atlantic islands: Portugal developed sugar plantations worked by enslaved Africans on Madeira and then on São Tomé (from the 1490s). São Tomé became a model of the plantation system that would later spread across the Americas.

Across the Atlantic, 1500 to 1650

• At first, enslaved Africans were brought to the Americas by way of Spain. In 1518 the Spanish Crown began issuing licences to carry captives directly from Africa, and by the mid-1520s ships were making that crossing.
• Demand grew as Indigenous populations collapsed and as Spain restricted Indigenous slavery (New Laws, 1542). Enslaved Africans worked in mines, cities, households and ranches in Spanish America; by the late 1500s, Mexico City and Lima had large African and Afro-descendant populations.
• Brazil: from the mid-1500s, Portuguese planters built sugar plantations and mills in Pernambuco and Bahia, first forcing Indigenous people to work and then turning increasingly to enslaved Africans. By around 1600 Brazil was one of the world's leading sugar producers.
• Africa's role: most captives were obtained by African states and merchants through war, raids and judicial punishment, and sold at coastal markets in exchange for cloth, metal goods, guns, alcohol and cowrie shells. The Portuguese colony of Luanda (founded 1576) in Angola became a major port, and Portuguese-led wars there produced many captives.
• The Middle Passage: captives were packed into ships for weeks or months. On average, more than one in ten died during the crossing, from disease, abuse and despair.

Scale: the SlaveVoyages database estimates that about 12.5 million Africans were forced onto ships between 1501 and 1866, and about 10.7 million survived to land in the Americas. By 1650 the trade had carried a fraction of that total (probably under one million by most estimates). Its great expansion came after 1650 (see the sibling unit The World, 1650–1789). But the systems, laws and justifications were built in this period.

African responses and resistance

• Rulers: Afonso I of Kongo protested illegal enslavement in 1526 (see African States: Songhai, Kongo, Benin, Ethiopia and the Swahili Coast). Queen Njinga of Ndongo and Matamba (about 1583 to 1663) negotiated with the Portuguese at Luanda in 1622, then fought them for decades, even allying with the Dutch, who held Luanda from 1641 to 1648. She is honoured in Angola today as a symbol of resistance. Like Afonso, she also took part in the trade in captives, a reminder that history's actors are complicated.
• Enslaved people resisted in many ways: shipboard revolts; escape; maroon communities of people who freed themselves, such as Palmares in the interior of Brazil, which grew from the early 1600s, and the community led by Gaspar Yanga in Mexico, which won recognition as a free town from Spanish authorities in the early 1600s; slowing work; keeping languages, religions, music and family ties alive; and using colonial courts and church institutions to seek freedom.
• Cultural survival: African religions, foods, music and languages blended with others to create new Afro-American, Afro-Caribbean and Afro-Brazilian cultures that shape the Americas today.

Slavery and what is now Canada

Slavery reached New France in this period too. In 1629 a young African boy, brought from Madagascar or West Africa by English privateers, was sold in Quebec; he is the first recorded enslaved African in New France. He was later baptized and given the name Olivier Le Jeune. Slavery of both Africans and Indigenous people (panis) existed in New France and later in British North America until the British Slavery Abolition Act took effect on 1 August 1834. Since 2021, Canada has officially recognized 1 August as Emancipation Day.