3.4 The Trans-Saharan Slave Trade

The Role of Kanem-Bornu

In about 900 CE, an empire called Kanem arose in the Central Sudan, located to the east of Ghana, Mali, and Songhai, and confined initially to the northeast of Lake Chad. The accession of Humai I to the throne of Kanem in 1087 marked the beginning of the Muslim Sefuwa dynasty. Around the same time, a fixed capital was established at Njimi, east of Lake Chad. Over the course of the next century and a half, the mais (kings) of Kanem established their control over the region. As in Ghana, the key to establishing and exercising this power was control over the desert caravan routes (Figure 3.20).

Figure 3.20 Trans-Saharan Trade. Trans-Saharan trade routes (red dotted lines) were a key factor in the development of the Kanem-Bornu Empire, which resulted from the expansion of the Kanem Empire south into Bornu along the western shore of Lake Chad. (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

It was under Dunama Dibbalemi in the thirteenth century that Kanem reached the height of its power and influence. Commanding a cavalry force of some forty thousand, Mai Dunama II gained control of the Lake Chad basin and extended the state’s control over the trans-Saharan trade northward as far as the Fezzan (southern Libya). Before the end of his reign, he established diplomatic relations with the kings of North Africa, especially in Tunis, thus ensuring the safety of caravans journeying to the distant south from the Mediterranean coast. This achievement guaranteed an increase in cross-Saharan traffic.

Although the Kanuri, the people of Kanem, mainly exported ivory and ostrich feathers, they also specialized in the selling of captives to the Muslims of North Africa and later to Europeans, notably the Portuguese who paid in guns and horses. The raids that produced these captives were justified in the name of jihad or holy war against unbelievers, a practice that led to conflict between Kanem and its neighbors.

By the mid-thirteenth century, Kanem dominated the Central Sudan. The empire extended as far west as the Niger River, as far east as the Wadai Sultanate (in eastern Chad), and north to the Sahara Desert. Crowning the Kanuris’ achievement during this period was the establishment of a tributary state in Bornu, southwest of Lake Chad. Over the course of the next century, however, Kanem became overstretched and weakened by wars and quarrels over succession, notably between the ruling Muslim Sefuwa dynasty, its sons, and the non-Muslim Bulala pastoralists east of Lake Chad.

Between 1376 and 1400, the rebellious Bulala, who opposed the imposition of strict Islamic rule under the Sefuwa, managed to assassinate five of the six Sefuwa kings. The result of this strife was a destabilized empire, which forced Mai Umar ibn Idris to abandon the capital at Njimi altogether. He led many of the empire’s Kanuri to Bornu, in the savanna region on the western shore of Lake Chad, where they permanently settled (Figure 3.21). Bornu was better situated to give the kings of the Sefuwa dynasty access to a wider trading network, and it already had established vital trading links with the Hausa kingdoms to the west.

Figure 3.21 Kanem-Bornu. The kingdom of Kanem-Bornu was less a kingdom than the conjoining of two city-states, Kanem and Bornu. The longest-lived of all the African kingdoms, Kanem-Bornu depended primarily on trade in the enslaved, whom it acquired by raiding neighboring states. (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

The early decades of the sixteenth century witnessed a revitalization of the Sefuwa dynasty. Under Mai Idris Katakarmabe, who ruled from 1507 to 1529, the Sefuwa were able to defeat the Bulala. The Sefuwa also strengthened their grip on the people of Bornu as they entrenched their rule, prompting a series of internal revolts by the non-Muslim peasant population that they ruthlessly suppressed. The dynasty established firm control over the peasants of Bornu who, once they submitted to Islam, were no longer subjected to raids.

The prosperity of Kanem-Bornu was tied to the trans-Saharan trade in enslaved people destined for the markets of North Africa and the Atlantic coast. By the end of the fifteenth century, Kanem-Bornu was trading about five thousand captives annually. During the second half of the sixteenth century, Mai Idris Aloma strengthened his army by importing firearms from North Africa. While the Songhai army failed to modernize, the rulers of Kanem-Bornu established strong relations with the Ottoman Empire in North Africa and gained access to Turkish mercenaries and advisers, who were brought in to train their new army (Figure 3.22). These changes, combined with the empire’s position on the frontier of Islam in Central Sudan, enabled it to make deeper slave-raiding incursions against its non-Muslim neighbors.

Figure 3.22 The Military Might of Kanem-Bornu. Kanem warriors in the sixteenth century routinely raided nearby communities in Central Sudan to capture prisoners they sold to European slave traders. This image comes from The Earth and Its Inhabitants, published in Europe in the 1890s. (credit: “Group of Kanem-Bu warriors” by New York Public Library Digital Gallery/Wikimedia Commons, Public Domain)

Kanem-Bornu peaked under Aloma, whose administrative and military reforms survived to sustain the empire for more than one hundred years. By the end of the sixteenth century, however, the empire’s power had begun to fade. A century later, the state’s capacity to maintain its territorial integrity had diminished so severely that the king’s rule extended effectively only westward, into Hausaland (present-day northern Nigeria). In the space of a hundred years, Fulani from West Africa had made significant inroads against Bornu, and in 1808, they seized the capital of Ngazargamu. The last Sefuwa king was killed in 1846, but Africa’s longest-lived empire managed to continue under new rulers until nearly the end of the nineteenth century.

The Arrival of Europeans

Europeans had long known that there were three ancient trade routes through the Saharan Desert. In the western Sahara, the route ran from Taghaza to Timbuktu. Farther east, a second route connected the oasis town of Ghadames with trade centers in Hausaland. Finally, there was a route connecting the major Mediterranean port city of Tripoli with Bornu in the Central African interior. Centuries of caravan trade along these routes had not, however, made them any less hazardous. Thus, those who knew the routes and the location of key cities and oases, and who appreciated the inherent risks of Saharan weather patterns, were in the best position to control and profit from trans-Saharan trade. It was therefore in the best interest of the Muslim and Arab travelers and caravanners who possessed this knowledge to monopolize it. To share it would undercut their profits. Consequently, European maps of the African interior remained sketchy; distances were mere estimates, and the locations of important cities such as Timbuktu and Kano were a matter of guesswork. Add to this the threat of raids and the possibility of a hostile merchant population, and to Europeans the undertaking of a trans-Saharan journey by themselves seemed likely to be disastrous.

In the fifteenth and sixteenth centuries, however, pressures mounted on European powers to boost their sources of national wealth—an urgency inflamed by the discovery of the Americas and the expense of traveling and setting up competing colonies there. Increasingly, European states desired to circumvent the intermediaries who controlled the trade in exotic luxury goods and vital raw materials, such as Chinese silk, Indonesian spices, and African gold. It was no easy matter to wrest control from these merchants, whose monopolies were often supported by kingdoms and states that benefited from it. The challenge was quite severe for poorer European states, such as Portugal.

When the Portuguese began their voyages along the West African coast, their immediate goal was not to discover a new trading route to India; rather, it was to secure West African gold. Europeans had been aware of the region’s goldfields since the fourteenth century, when Sudanic gold had been imported as a raw material to mint European coins. By the mid-fifteenth century, the Portuguese had made inroads along the Senegambian coast, raiding Amazigh settlements on the island of Arguin (an extension of the trans-Saharan trade routes), taking captives to be enslaved on Iberian plantations, and exploring along the Senegal and Gambia Rivers in search of sources of gold. These ventures mark some of the earliest attempts at direct European involvement in trans-Saharan trade.

The Portuguese monarchy also hired explorers such as Alvise Cadamosto, a Venetian slaver sent to scout the region of Senegambia. These efforts gave the Portuguese an opportunity to develop a clearer sense of the scope of trans-Saharan trade, including interactions with the Wolof, who sold enslaved people along the interior trade routes in West Africa. A few decades after Cadamosto had met the vassal kings of Mali in the Gambia region, the Portuguese established Elmina (“the mine”), a fort on the African coast south of the Akan goldfields. Located in present-day Ghana, Elmina was a fortified trading post from which the Portuguese traded copper, brass, and cloth with Africans for Akan gold. The mines at Akan also relied on enslaved workers, whom the Portuguese bought from Benin and then sold to Mande-speaking Dyula traders. By the turn of the sixteenth century, the Portuguese had also entered West Africa’s cowrie-shell currency market, providing shells along with luxury goods to the regional market in exchange for still more gold. Progressively, they diverted traffic away from the centuries-old trans-Saharan trade routes and along the West African coast.

The Portuguese first laid eyes on São Tomé and Príncipe, a pair of islands in the Gulf of Guinea, in the 1470s. By 1500, they had successfully settled both, which were prized for their strategic location off the West African coast and for their tropical climate and volcanic soil, ideal for planting and harvesting sugar. It was not long before large-scale sugar plantations sprang up on the islands and the Portuguese entrenched themselves in the Gulf of Guinea. The production of sugar is a notoriously labor-intensive process and requires a huge workforce. African chiefdoms and coastal intermediaries had demonstrated to the Portuguese their willingness to sell captives whom the Europeans could enslave as laborers where needed. Indeed, as the plantation economy on São Tomé expanded, its need for slave labor grew. By the early sixteenth century, the island was Europe’s single largest sugar supplier and home to a vast enslaved workforce, which the settlers obtained from Elmina.

Less than forty years elapsed between the Portuguese settlement of São Tomé and Príncipe and the first trans-Atlantic voyages of African captives who were sold into slavery in the Americas. Recognizing an opportunity to profit, chiefs on the African mainland engaged in raids against their neighbors to generate captives they could sell to the Europeans—first to the Portuguese and later to the Dutch, Spanish, French, and English. As competition rose among the European powers to establish trading posts along the West African coast, tensions flared among African polities as they either engaged in or resisted the growing trade in enslaved people.

Then, when Songhai, the largest and most powerful of the Sudanic kingdoms in the sixteenth century, was shattered by the Moroccan army at the Battle of Tondibi (1591), the situation in West Africa was permanently altered. Without a powerful central authority, a host of small states emerged whose chiefs saw the benefits of dealing directly with wealthy Europeans rather than through the centuries-old system of caravan trade. These developments resulted in a dramatic change in the size and scope of the trade in enslaved Africans, from a few thousand people in the sixteenth century to tens of thousands in the seventeenth, and for much of the next century, an average of about forty-five thousand people per year.

The Later Trans-Saharan Slave Trade

Africa was transformed during the eighteenth century. This period witnessed the emergence of expansionist new states in West Africa, such as Dahomey and Segou, whose wars of conquest generated captives for European slavers. It also saw a sharp rise in conflict between African states and related growth in the trade in enslaved captives. Such growth came at the expense of the historical trans-Saharan trade network, which was disrupted and reoriented to prioritize the traffic in captive human cargo destined for coastal slave markets. While the overall numbers varied by location, the general trend was an increase in the number of captives being moved along the trans-Saharan corridors during the eighteenth century. This trade did more than benefit merchants; in many instances, it provided a boon to businesses and firms related to the slave trade that were located at trans-Saharan trading centers. The societies as a whole did not benefit, however, nor did the people who were enslaved. As a result of this altered state of affairs, the scope of the trans-Saharan trade in enslaved people doubled between the seventeenth and eighteenth centuries to an estimated 900,000 enslaved people.

The development of the trading state of Whydah provides a unique window into these dynamics. Situated in the Bight of Benin on the Gulf of Guinea, along what came to be called the Slave Coast, Whydah was transformed with the arrival of the Europeans in West Africa in the fifteenth century (Figure 3.23). By the seventeenth century, the French West India Company had moved its main trading site to Whydah, making it one of the region’s most important slave ports, second only to Luanda in Angola. By the end of the century, the Dutch West India Company, the English Royal African Company, and the Portuguese all had moved their slave markets to Whydah. Several of these European powers went on to establish coastal trading forts there. Between 1650 and 1690, the number of captives brought to Whydah in caravans increased dramatically, from about one thousand people per year to about ten thousand. It is estimated that in the quarter-century between 1700 and 1725, fully a third of all captives coming from Africa—approximately 378,000 of them—were taken out of Whydah.

Figure 3.23 Crowning a King on the Slave Coast. The kings of Whydah had a very close relationship with the European slavers who established trading centers along the Gulf of Guinea. In this French etching from about 1725, a new king is crowned before an audience that includes Europeans. (credit: “Coronation ceremony for the King of Whydah” by Gallica/Wikimedia Commons, Public Domain)

Whydah’s flourishing trade in enslaved people did not result from wars waged by its own rulers, but from its location at the end point of trade routes between battling factions. One route originated from the former Mali Empire. Some captives from there wore Muslim clothing and had been in transit for three months before arriving in Whydah. Another route originated in the Yoruba kingdom of Oyo, which was engaged in a series of wars against the neighboring kingdoms of Nupe and Borgu. The value of enslaved captives passing through Whydah was enormous, and the slave trade benefited both the African slave merchants and the state, which was entitled to customs duties and taxes. From providing porterage services to supplying food and other necessities that made the trade possible, local businesses also profited from the sale of enslaved people. As elsewhere, the transport and sale of captives into slavery produced a profitable economy for virtually everyone involved, except for the enslaved people.

In 1727, King Agaja of Dahomey conquered the kingdom of Whydah and incorporated it into his own (Figure 3.24). The fall of Whydah was part of a larger campaign by Agaja to restore traditional social and political controls over the region, which was then home to several smaller Aja kingdoms including Dahomey. By 1737, Agaja had conquered the entire Slave Coast and brought it under Dahomey’s control. However, initially Dahomey was reluctant to continue the practice of selling Africans to Europeans. This was not to the liking of the kingdom of Oyo, whose foreign trade depended on it. By the middle of the century, near-constant warfare against Oyo, which disrupted interior trade routes and hurt both kingdoms economically, convinced the rulers of Dahomey to abandon their reluctance. They opted instead to exercise strict royal control over the Slave Coast trade. Dahomey went on to become one of the major exporters of enslaved captives, which the state traded in exchange for firearms. By the end of the century, Dahomey had become one of the most heavily armed and militarized states in West Africa.

Figure 3.24 The Slave Coast. New states like Whydah and Dahomey emerged along the Gulf of Guinea coast in the eighteenth century. These states were formed primarily as a result of the European slave trade, which is why this coastal region was known as the Slave Coast. (attribution: Copyright Rice University, OpenStax, under CC BY 4.0 license)

As Agaja and his successors extended their control over the Gulf of Guinea, the frontier of the slave trade on the West African coast was pushed deeper into the African interior, beyond the kingdoms that ranged along the Senegambia. It is estimated that well over half the captives taken and sold during the eighteenth century came from the far interior, many from the Kingdom of Segou, located southwest of Djenné on the Middle Niger in Mali.

Founded by Mamari Kulubali in 1712, Segou made warfare a way of life. The Segou kingdom’s economy was trade based, and its essential trade good was enslaved people the state acquired through raiding and warfare waged against its neighbors. These incursions reached as far as north as the Niger Bend and Timbuktu, which the Segou briefly occupied. Once captured, those seized by the Segou military faced two possible fates: they could be sold to desert nomads as part of the trans-Saharan slave trade, or they could be sold to caravan merchants who dealt with European slave traders on the Slave Coast.

Although perhaps most pronounced in West Africa, the altered dynamics of trans-Saharan trade in enslaved people in the eighteenth century were also apparent in North Africa. Scholars have estimated that the Maghreb, encompassing Morocco, Algeria, Tunisia, and Libya, received an average of six thousand enslaved Africans every year between 1700 and 1799. About fourteen hundred enslaved people a year passed through Ghadames and the oases center of the Fezzan in Libya, both historically vital to the trans-Saharan trade between Central Sudan and Tripoli. But by midcentury, these centers—also the destination points for some caravans from West African trade centers such as Timbuktu—were sending larger caravans of captives to the markets at Tripoli. By the end of the eighteenth century, the numbers of the enslaved bound for market along the Mediterranean coast had increased by as much as a quarter, making the trade in enslaved Africans through Tripoli a key component of the region’s economy.