GWYN CAMPBELL. “The East African Slave Trade, 1861-1895: The ‘Southern’ Complex, The International Journal of African Historical Studies, Vol. 22, no. 1 (1989): 1-26.

ABDUL SHERIFF.  Slaves, Spices, and Ivory in Zanzibar: Integration of an East African Commercial Empire into the World Economy, 1770-1873. Athens: Ohio University Press, 1987.


The readings for this week are the second in a series of two case studies on specific regions of East Africa in the eighteenth century. East Africa is an area that includes Mozambique and the Great Lakes Region. Situated on the western Indian Ocean, this region corresponds to the present-day coasts of Mozambique, Tanzania, and southeastern Kenya, as well as Madagascar and various nearby islands like Comoros, Mayotte, Réunion, and Mauritius. The area also includes many hinterland regions of Eastern Africa, such as present-day Zimbabwe, Malawi, Zambia, the Democratic Republic of Congo, Rwanda, Burundi, and Uganda. In the late-eighteenth and nineteenth centuries, the principal ports of Eastern Africa were Sofala in Mozambique and Zanzibar in Tanzania. These ports were occupied mainly by Swahili, Portuguese, Omani, and Indian traders. The readings assigned for this week are both secondary sources, one on south and one on north East Africa. The first is an article on slavery in late-nineteenth century Mozambique by Gwyn Campbell. The second is an historical survey by Adbul Sheriff entitled Slaves, Spices, and Ivory in Zanzibar.

Gwyn Campbell’s “The East African Slave Trade”

In his article, “The East African Slave Trade,” the historian Gwyn Campbell re-investigates the nineteenth-century history of what scholars often call the “southern” East African slave trade.[1] This slave trade took place on the coast and in the interior of present-day Mozambique from Kilwa southward. Campbell argues that slave-importing and exporting islands located in the western Indian Ocean, especially Madagascar, are “the ‘missing link’ in the history of East Africa in general and of the East African slave trade in particular.”[2] He observes that historians have appreciated the degrees to which some foreign markets have shaped the East African slave trade, such as those in the Persian Gulf and those in Cuba and Brazil before that export trade was closed around the 1850s. Nonetheless, historians have not fully appreciated the “trans-Mozambique Channel trade,” which flourished in the last three decades of the nineteenth century, carrying East Africans from modern-day Mozambique to burgeoning markets on Madagascar and then to its surrounding islands.[3] As a way to address this gap in the literature, Campbell positions Madagascar at the center of the history of the East African slave trade. He covers from the re-opening of the Merina Empire of Madagascar to foreign investment in 1861 to the French takeover of Madagascar in 1895.[4]

Campbell traces the history of the East African slave trade in the late-nineteenth century to a series of new “manpower” or “labor shortages” in the western Indian Ocean. French traders from the Mascarene islands addressed these labor shortages in their colonies by buying enslaved people from Swahili and Arab traders on the coast of Mozambique, and also by purchasing East African or Malagasy slaves from markets in Western Madagascar.[5] Likewise, the Merina Empire handled its own labor problems by importing and then often re-exporting East Africans from Mozambique, while also exporting certain peoples form the interior of Madagascar. Meanwhile, an entire cast of intermediaries emerged to facilitate Madagascar’s “two-way traffic in slaves.”[6] This cast included traders of Arab origin in Northwest Madagascar, called Antalaotra; traders of British-Indian origin in the same area, called Karany; and various kingdoms, republics, and private traders on the coast and interior of Madagascar. Examples of this last group are Sakalava and Bara chiefs, the Betsiriry and Antanosy slave communities, and independent Mascarene middlemen like the Samat and Rossier brothers, all of which generally worked in the southwest of the island.[7] Finally, Campbell adds to this diversity European, South African, and American traders working in the region.[8]

In addition to exploring the makeup of Madagascar-based slaving communities, Campbell also explores the slaving structures on the East African coast and interior. Here, Swahili and Arab traders are supplied with slaves from intermediaries like Malawi chiefs, despite attempts by Portuguese and British authorities to terminate the slave trade. In fact, throughout the period Campbell focuses on, the British are working to police the East African slave trade. Campbell demonstrates, however, that they are not effective. The trade grows exponentially during these years, even as the British are much more successful in their suppression efforts to the north at Zanzibar.[9] In fact, one of Campbell’s more interesting conclusions from this article is that the southern branch of the East African slave trade prospered, in part, because the British were more effective in closing the northern slave routes. The growth of the southern slave trade out of Mozambique, as Campbell explains, both expanded and deconcentrated in response to British activity up north. Slave traders, moreover, adopted a series of “evasive tactics” for circumventing British police action, and the British halted much of their policing action after the Franco-Merina War of 1882-1885. From this period onward, the British began to formally recognize French sovereignty in Malagasy waters.[10]

Finally, Campbell provides his readers an overview of what a “trans-Mozambique Channel run” entailed. He describes the shallow-draft, small, and fast boats that Arab traders used in tandem with their intimate knowledge of the coast to evade British patrols. He describes the high mortality rates for slaves aboard these ships, probably as high as 25%.[11] Nonetheless, the trade was exceedingly popular during the 1880s. Traders made profits of 1,000% and well over 20,000 slaves were exported from the East African coast to Madagascar and the French colonies each year.[12] Although these numbers never reached the export figures of Zanzibar during its height, the slave trade from southern East Africa was sustained throughout the late-nineteenth century by these three new markets: Western Madagascar, the French isles, and Imerina or the Merina Empire.[13] In a final section, Campbell discusses some of the causes that led this slave trade to decline at the close of the nineteenth century. These include British anti-slavery agitation within the hinterland of East Africa as well as French enforcement of their 1896 proclamation abolishing slavery in Madagascar. However, in the prior three decades, the Mozambique channel trade had been characterized by violence. The trade had devastating effects on enslaved Makau, Mijana, and Malagasy peoples.

Adbul Sheriff’s Slaves, Spices, and Ivory in Zanzibar

In Slaves, Spices, and Ivory in Zanzibar, the Tanzanian historian Abdul Sheriff has revised his 1971 dissertation titled “The Rise of a Commercial Empire: An Aspect of the Economic History of Zanzibar, 1770-1873.”[14] Sheriff revisits this earlier historical narrative of Zanzibar from a Marxist theoretical lens. He traces the history of the East African island of Zanzibar from being a collection of Swahili coastal states, to being a major port of the Omani-Swahili “commercial empire” in the late-eighteenth century, to being a political satellite of the British Empire in the early 1870s. Sheriff focuses mostly on Zanzibar’s development as a mercantilist state based around three products that were central to its regional economy: slaves, spices, and ivory. In doing so, he shows that Zanzibar functioned as an economic intermediary between East Africa and foreign markets in India, Western Europe, and the United States.[15] He concludes that Omani-Arab domination over the Swahili coastal states, Zanzibar’s expansion into the East African interior, and, finally, Zanzibar’s colonial takeover by Britain must all be understood as originating from global economic relations. Each of these major historical transformations “involved the subordination of merchant capital to serve the needs of the emerging capitalist mode of production on a world scale.”[16] As early as the late-1700s, Britain and the USA were at the center of this world capitalist system.

With Slaves, Spices, and Ivory in Zanzibar, Sheriff has produced an impressive commercial history of an East African island that stood at the center of the region’s economy. For sources, he has drawn on archival materials from India, France, Britain, and the United States.[17] He has presented the region’s commercial history in both quantifiable form, with a series of tables and graphs, and in qualitative form, through the writings of merchants, politicians, and other important figures. As a regional survey, Sheriff’s book builds upon the previous writings of historians like Frederick Cooper, C.S. Nicholls, and Norman Bennett.[18] However, prior scholars often emphasized political agency and Arab imperialism through discussions of figures like Seyyid Said bin Sultan, founder of the Omani State in Zanzibar. In contrast, Sheriff emphasizes global and international economic structures à la Marxist-, dependency-, and world-systems theories. He has worked Marxist terminology into his narrative, writing of “merchant classes,” “mercantile bourgeoisies,” “pre-capitalist modes of production,” and “landed aristocracies.”[19] More importantly, he writes of “British overrule,” “British overlords,” and “British overlordship.”[20] His main thesis is that the Omani State in in Zanzibar was an “economic and political agent” of capitalist Britain by the late eighteenth century.[21] Britain conquered East Africa economically a century before the Berlin Conference.[22]

What is the trajectory of Sheriff’s history? The story begins with East Africa as a collection of Swahili city-states “like beads in a rosary, each forming a distinct entity, and yet threaded together by maritime communication and a common culture and language.”[23] By the end of the fifteenth century, Portuguese merchants have arrived on the coast and started setting up trading centers. Then, in the mid-seventeenth century, the economy of Oman on the southern Arabian peninsula transforms to become one dependent on coastal trade and black slavery. Omani merchants in search of slaves travel down the coast of East Africa. From 1698 to 1729, they drive the Portuguese from the northern part of East Africa and established themselves as the new protectors of the Swahili coastal states.[24] After usurping the Portuguese, Omani traders become the main exporters of slaves from East Africa to markets in the western Indian Ocean. Thus, Zanzibar becomes a commercial colony of the Busaidi dynasty based in Muscat, Oman. Its trade in East African slaves grows in the mid-eighteenth century when the French establish colonies on the Mascarene Islands off the coast of eastern Madagascar (Mauritius, Réunion, and Rodrigues). Meanwhile, the British are beginning to consolidate their power over both the Persian Gulf and Bombay, India. Alongside the French islands, these areas become the main foreign markets of the Busaidi dynasty.

The last quarter of the eighteenth century is a turning point in Sheriff’s history of Zanzibar. By the 1770s, the complete nature of the Omani “commercial empire” has begun to take shape. As Sheriff argues, the Omani State in Zanzibar is a “compradorial state.” Sheriff borrows the term of “compradorial” from Marxist Chinese literature. It derives from a Portuguese word for ‘purchaser.’ It refers to a commercial polity that is run by “local agents of foreign capital or interests.”[25] Essentially, Sheriff is saying that Omani-Zanzibar is a polity that is, on its surface, both built and run by a vanguard of merchant princes from Oman. However, these princes are ultimately dependent for survival upon access to foreign markets that are outside of their control.[26] In this sense, merchants under the Sultan of Oman were the ones who brought international capitalism to East Africa. However, these merchant classes from the Busaidi dynasty were never in control of this emerging capitalist system. In fact, the merchants shortly became just “a tool of British capital.”[27] Sheriff summarizes this point and clearly articulates his book’s thesis: “from the end of the eighteenth century the compradorial state had also been politically dependent on Britain to protect itself from its rivals, particularly in the Persian Gulf, and to gain access to the British Indian market.”[28]

The majority of Sheriff’s study is dedicated to narrating and analyzing the nineteenth century history of Zanzibar, with the goal of proving his thesis about the “compradorial state.” Sheriff shows, for example, how Omani traders in Zanzibar attempted to follow the French colonial model and install their own plantations on Zanzibar, Pemba, and the East African coast. But these traders based their local economies on the production of cash crops such as cloves and raw materials such as ivory. Since they could not control the prices of these products on the world market, they could not control success. Likewise, Busaidi trade grew during the Napoleonic Wars because British and Indian ships sailed under Omani protection, and the Omani fleet seized European prizes to increase its size. But this bubble burst in 1817, and thereafter the British engaged in commercial policies to severe the African side of the Omani Empire from its Arabian side. Under the “guise of a humanitarian crusade against the slave trade,” Britain worked to reduce Zanzibar to an economic outpost of their empire.[29] They used a series of Anti-Slavery Treaties, notably in 1822 and 1845, to curtail the size of the Indian Ocean slave trade and to ultimately ensure the priority of British markets for East African goods. The fact that British merchants had no compunctions about these goods being produced by domestic slaves in East Africa lends the lie to their humanitarian motives.

Sheriff provides a wide range of evidence to demonstrate how the Omani State in Zanzibar was economically subservient to a world capitalist system run by Britain. To provide just one more example, Sheriff shows how Britain leveraged military and commercial power to direct the course of Zanzibar’s political history. After the death of Said in 1856, British authorities worked to set up one of his sons, Majid, as their proxy ruler in Zanzibar. This maneuver involved supporting Majid’s “right” to secede from the rest of the Busaidi dynasty, even though Britain had prevented a similar attempt to breakaway by the Mazrui of Mombasa in the previous century.[30] In this instance, Sheriff shows how the attitude among British agents about what the people of Zanzibar wanted or needed was shaped by what option was the most economically advantageous to their empire. After breaking the African half of the Omani Empire away from the Arabian half, British authorities renewed their efforts to control East African production via the Anti-Slavery campaigns. These efforts culminated in a new Treaty of 1873 that shut down the slave trade and further subordinated the Zanzibari economy to British markets. When Britain began official colonization of the region with the Heligoland Treaty of 1890, East Africa was already under British control. Sheriff argues that this treaty was only formal recognition of what had already become a political reality.

Comparing Campbell and Sheriff on East Africa:

What are a few points upon which we can compare Campbell’s article on the Mozambique trade with Sheriff’s book on Zanzibar? First, Campbell’s chapter might provide some support for Sheriff’s claim that British politicians were less interested in ending the slave trade than they were in controlling the economic markets of the western Indian Ocean. While Campbell is far less cynical about the intentions of British anti-slavery activists, he demonstrates that British efforts to end the slave trade in northern East Africa resulted more in that trade moving southeast to new markets than in its ending entirely. I can imagine these two historians arguing about whether British activists were really humanitarians, while agreeing that the result of their anti-slavery efforts were far what they claimed. In other words, whether British anti-slavery campaigners really desired to end slavery in East Africa, the point is that they failed to do so and that their policing campaigns were more effective in achieving something else: establishing British commercial and political hegemony in the region. Nonetheless, there seems to be a major tension between Sheriff’s arguments and Campbell’s conclusions. Sheriff argues that the British were in control of the new world capitalist system, yet what did this control mean in practice if British agents could neither anticipate the rise of the slave trade in the Mozambique channel or control its operation once it began?

Ultimately, Sheriff and Campbell have written two historical works that are philosophically opposed. Sheriff’s study of Zanzibar is a structuralist analysis. As such, it depends on relationships between classes of people rather than the intentions that those people hold. Many critiques of Sheriff’s book in the reviews have focused on its “impersonal” nature, supported by its Marxist framework. Indeed, much of the book is written in passive voice and, while historical actors are used to reveal economic relationships, they are generally representatives of larger concepts. The “material interests of rising British capitalism,” for instance, are shown through the actions of British agents, but they do not depend upon the choices of any single agent.[31] Likewise, the “merchant capital” of the Busaidi dynasty acts as exemplars of “merchant capital” throughout History rather than people who make unique choices and, therefore, must be held accountable for them. Broadly put, Sheriff’s work is great at revealing how power transcends individual and group agency. But in downplaying agency, Sheriff’s work also seems deterministic. His Marxist analysis gives us a wider perspective on international relations, but we also lose what is nice about Campbell’s chapter. This is the sense that History is also shaped by consequences that can be unintended and unpredictable.


[1] Gwyn Campbell, “The East African Slave Trade, 1861-1895: The ‘Southern’ Complex, The International Journal of African Historical Studies, Vol. 22, no. 1 (1989): 3.

[2] Campbell, “The East African Slave Trade,” 3.

[3] Ibid. 3.

[4] Ibid. 4, 7.

[5] Ibid. 5.

[6] Ibid. 6.

[7] Ibid. 9-11.

[8] Ibid. 18-19. On this note, Campbell also observes that goods manufactured in overseas markets like Britain and America “constituted the prominent articles of exchange” for slaves in this period. This included cloth, firearms, gunpowder, etc.…

[9] Ibid. 17. Campbell writes, “Thus although the campaign against the slave trade in East Africa achieved considerable success in the Zanzibar region by 1888, a vigorous slave trade was maintained via the southern network.”

[10] Ibid. 21. By “evasive tactics,” Campbell is largely referring to the strategic deployment of national colors/flags on boats. But it also includes other tactics, such as passing off small groups of slaves as crew members (22).

[11] Ibid. 9-11.

[12] Ibid. 19, 23.

[13] Ibid. 23. A table breaks down import figures for these three markets from the 1860s to the 1890s (24).

[14] Abdul Sheriff, “The Rise of a Commercial Empire: An Aspect of the Economic History of Zanzibar, 1770-1873” (PhD Dissertation, University of London, 1971).

[15] Abdul Sheriff, Slaves, Spices, and Ivory in Zanzibar: Integration of an East African Commercial Empire into the World Economy, 1770-1873 (Athens: Ohio University Press, 1987), 1.

[16] Sheriff, Slaves, Spices, and Ivory in Zanzibar, 245.

[17] Ibid. ix. See also Sheriff’s discussion of sources on 259-260.

[18] See, for example, Federick Cooper, Plantation Slavery on the East Coast of Africa (New Haven: Yale University Press, 1977); Norman Bennett, A History of the Arab State of Zanzibar (London: Methuen and Company Limited, 1978); and C. S. Nicholls, The Swahili Coast: Politics, Diplomacy, and Trade on the East African Littoral, 1798-1856 (London: Allen and Unwen, 1971). As Sheriff demonstrates, the historiography of Arab-Omani imperialism was advanced earlier by Reginal Coupland, East Africa and its Invaders: From the Earliest Times to the Death of Seyyid Said in 1856 (Oxford: Clarendon Press, 1938). It has been furthered by Kenneth Ingham and Ralph A. Austen in more recent years. See Sheriff, Slaves, Spices, and Ivory in Zanzibar, 5, 33-34.

[19] Ibid. 3, 16, 77, 246.

[20] Ibid. 24, 29.

[21] Ibid. 30.

[22] Ibid. 202.

[23] Ibid. 8.

[24] Ibid. 26.

[25] Ibid. 7, n.6.

[26] Ibid. 17.

[27] Ibid. 78.

[28] Ibid. 5.

[29] Ibid. 218.

[30] Ibid. 214.

[31] Ibid. 28.