The reparations campaign argues that Britain’s imperial dominance was built on the profits of the slave trade. If that argument is correct, it carries a clear implication: nations that participated more extensively in the slave trade should have built more powerful empires. The comparative historical record destroys that implication.
Portugal transported approximately 5.8 million enslaved Africans across the Atlantic, against Britain’s 3.1 million. Portugal was the originator of the Atlantic slave trade, dominant in it for over 150 years before Britain became a serious participant, and active in it for longer than any other nation. If slave trade profits were the engine of imperial power, Portugal should have become the dominant global empire. It did not. By the eighteenth century, Portugal was one of the weaker European powers, economically dependent on Britain, its empire largely contracted to Brazil and a scattering of coastal trading posts. In 1755 Lisbon was destroyed by an earthquake and rebuilt largely with British financial assistance. Portugal’s participation in the slave trade at a scale nearly double Britain’s produced no industrial revolution, no global naval supremacy, and no century of unchallenged imperial dominance.
Spain was another major slave-trading nation with a vast American empire producing enormous commodity wealth. The Spanish Empire at its height controlled more territory than any empire in history up to that point. Yet Spain did not industrialise. It did not develop the naval and commercial dominance that Britain achieved. The flow of silver and slave-produced sugar and tobacco into Spain produced inflation, not industrial development, and by the nineteenth century Spain was a declining power that had lost most of its American colonies.
The Netherlands was a significant participant in the slave trade and a major colonial power in the seventeenth century. Dutch merchants were sophisticated, their capital markets advanced, their trading networks global. Yet the Industrial Revolution did not happen in Amsterdam. Dutch commercial power peaked in the seventeenth century and declined relative to Britain thereafter, despite comparable or greater engagement with the colonial and slave-trading economy.
France transported approximately 1.4 million enslaved Africans, ran highly profitable Caribbean plantations, and was Britain’s primary imperial rival throughout the eighteenth century. French slave trade profits, by the logic of the Williams thesis, should have been a powerful driver of French industrialisation. They were not. France industrialised later and more slowly than Britain, and French imperial power in the nineteenth century consistently lagged behind British.
The pattern across all the major slave-trading nations is consistent: there is no correlation between the scale of participation in the slave trade and the degree of industrial development or imperial power that followed. The nation that industrialised first and most powerfully was Britain, but Britain was not the largest slave trader. The largest slave trader was Portugal, which remained an economic backwater. The second largest was Spain, which deindustrialised rather than industrialised on the back of its colonial wealth.
What distinguished Britain was not the scale of its slave trading but the combination of coal, legal institutions, capital markets, geographical security, and practical innovation described elsewhere in this section. Those factors were independent of the slave trade and were not shared by Portugal, Spain, or the Netherlands despite their greater or comparable involvement in enslaved labour.
The Williams thesis requires the slave trade to be the decisive variable in British industrialisation. The comparative evidence shows it was not a decisive variable at all. If it had been, Portugal would have industrialised first, Spain would have industrialised second, and Britain’s Industrial Revolution would have needed a different explanation. The explanation that actually works has nothing to do with slavery.
