The German philosopher Hegel claimed that Africa “is no historical part of the world”. The corollary of this was taken to be that African history only began when Europeans started to arrive. This idea, and variants of it, became one of the fallacies deployed to justify the Atlantic slave trade, colonisation and the high-handed paternalism that characterised European rule right up until decolonisation in the 1960s. Even before the flags of the European colonisers had been lowered, and the newly independent nations of modern Africa emerged, urgent calls had been made for new histories of the continent that explored the longer and deeper history of Africa’s great civilisations.

Sadly, that corrective is still necessary as, outside of the continent, Africa’s past continues to be understood largely through the colonial era of the 19th and 20th centuries. Yet at times discussions of African history can become ensnared by a false dichotomy, a choice between the familiar, Eurocentric narrative – dominated by explorers, missionaries, gun boats and the Maxim gun – and a more Afrocentric story, focusing on pre-colonial Africa. This line in the sand, drawn between two forms of history, can obscure a key point; that before formal colonisation in the 19th century were several centuries of contact and interaction with outsiders, and not just Europeans. It is those centuries of interaction and their long-term economic impact on Africa that are explored in unusual detail in Toby Green’s remarkable new book, A Fistful of Shells: West Africa From the Rise of the Slave Trade to the Age of Revolution.

Not an easy work to categorise, it is at its core an economic history in which the author poses a profoundly challenging question. Why, he asks, did economic exchanges between Africa and Europe become so unequal over time – favouring the latter and inhibiting African societies’ ability to accumulate capital – and what role did the Atlantic slave trade come to play in this process? The ambition of the central thesis explains the scale of the book – more than 600 pages – yet this seems almost restrained given how widely Green casts his net.

A Fistful of Shells is the fruit of research conducted in the archives of nine nations and required the author to undertake fieldwork across eight West African states. It shows. Passages from the author’s travels provide observations and anecdotes that usefully link the past to the present day and give voice to the lives and experiences of African themselves. Ranging far beyond economics, Green’s thesis becomes, ultimately, an almost philosophical meditation on the nature of value across differing cultures and societies during a long and under-examined era of early globalisation.

What marks the book out as unusual is not the volume of sources but their range. The use of oral histories from an impressive array of African societies is particularly refreshing. In his introduction Green also brilliantly deploys fine art – a series of portraits by a Dutch artist painted in mid 17th century Brazil, parts of which were then ruled from Amsterdam. One painting shows the face of Dom Miguel de Castro who, despite his Portuguese name and flamboyant European dress, was an ambassador from the court of Kongo, an African kingdom then allied to the Dutch. The same portrait astonished visitors to last year’s Histórias Afro-Atlânticas exhibition in São Paulo.

This breadth of material makes it interesting to wonder if Green might have been able to paint an even more vivid panorama of this earlier period had he been able to call upon the 15th and 16th century archives of Portugal, the European nation with the longest history of trade to Africa. Many of those records – concerning trade but also diplomacy, war and missionary work – along with an unknowable amount of material culture, were lost in 1755 when an earthquake and tsunami devastated Lisbon (the disaster at the centre of Voltaire’s Candide), obliterating the city and expunging the ledgers that recorded the preceding three centuries of the African trade. The frailty of documentary sources and material culture is poignantly highlighted again through Green’s use of a war standard sent to Lisbon by the infamous King Adandozan of Dahomey (a state located in present-day Benin). Although reproduced here, the standard itself was lost to the fire that destroyed the Museu Nacional in Rio de Janeiro in 2018.

By bringing together so many sources Green is able to refute Hegel’s negation of African history on two levels; not only does Africa have a long and complex history, but it shares much of that past with other players in a global trading economy that stretches back over a millennium. The Africa that emerges here is one dominated by numerous powerful kingdoms and empires, often governed by strong dynasties and leaders, each with their own obsessions and ambitions. It is a continent of intricately complicated cultural and religious beliefs and practices, in which militarised and sometimes relatively urbanised societies rise and fall. In other words, African societies were little different in structural terms from the kingdoms of Europe and North Africa with whom they traded. Where differences came to be acute was in the meanings and values attached to various goods and commodities, including the cowrie shells of the book’s title. Shipped to Africa from the Maldives in the Indian Ocean in vast quantities and over several centuries, cowries were used as a form of currency by many African peoples.

The trade in ideas, technologies, art and culture between Africa and her partners flowed both ways, a reality that was accentuated by the slavery trade – something that Green explores in great depth. Not only did African goods and commodities pulse through the arteries of the Atlantic world, cultural knowledge and intellectual capital was taken to the New World in the minds of the millions of human beings who were themselves commodified and exchanged. The Maroons, communities of escaped slaves that emerged in Jamaica, Panama and elsewhere, fought their wars using military theories they had learnt on the continent of their birth. Likewise, the rice plantations of South Carolina were cultivated using not just African labour but also African knowledge. This expertise was intentionally transplanted into American soil by British slave traders who had enslaved thousands of people from the rice-growing regions of Sierra Leone. These Africans were kidnapped to order, their minds as valuable a commodity as their bodies.

Throughout A Fistful of Shells Green points to the long historical shadow that lies behind the underdevelopment of modern Africa. He argues that the cash-crop monocultures imposed upon African nations by the colonial powers in the 20th century partially have roots in the plantation economies of the 19th century, when powerful African leaders, encouraged by Britain and other states, use enslaved and coerced labour to grow cotton, peanuts and palm oil for export. Likewise, the general distrust in national leaders in 21st century Africa, Green feels, has links to the 17th and 18th century ruptures in the relationship between elites and their people, caused by the slave trade and the wars and instability it propagated.

Although not always the easiest text to follow – the thematic approach at times obscuring the sense of a developing narrative – this is a stunning work of research and argumentation. It has the potential to become a landmark in our understanding of the most misunderstood of continents.

David Olusoga’s books include “Black and British: A Forgotten History”

A Fistful of Shells: West Africa from the Rise of the Slave Trade to the Age of Revolution

Toby Green

Allen Lane, 656pp, £30