The story of the so-called ‘Scramble for Africa’ – the period between roughly 1876 and 1912, when European nations added almost 10 million square miles of the continent and 110 million new subjects to their overseas colonial possessions – is well known to British readers. Less familiar is the tragic sequence of events at the heart of the process: the ruthless exploitation of the Congo River basin by Zanzibari traders, King Leopold II of Belgium and the French government.

A huge area roughly the size of the United States east of the Mississippi River, the Congo basin rainforest was characterised by its many languages, ethnic groups and distinctive ‘small-scale political units with flexible forms of leadership and authority’. But all this would change in the late 19th century as intruders arrived from both east and west. ‘From the East African coast’, writes Robert Harms, a professor of history and African studies at Yale, ‘came Arab and Swahili traders – subjects of the sultan of Zanzibar – in search of ivory and slaves. They were followed closely by British explorers looking for the source of the Nile, a quest that led Henry Morton Stanley to follow the Congo River downstream to the Atlantic Ocean in 1877.’ That same year, the Italian explorer Pierre Savorgnan de Brazza, with support from the government of France, entered the watershed of the Congo River from the west by traversing the Crystal Mountains.

It was the start of a brutal process of exploitation. Merchants

in search of ivory, captives, and rubber, who operated under the authority of the sultan of Zanzibar, the king of Belgium, or the government of France, entered the rainforest to strip it of its bounty. Ordinary people