From 1885 to 1908, many atrocities were committed in the Congo Free State (today the Democratic Republic of the Congo) under the absolute rule of King Leopold II of Belgium. These atrocities were particularly associated with the labour policies, enforced by colonial administrators, used to collect natural rubber for export. Combined with epidemic disease, famine, and falling birth rates caused by these disruptions, the atrocities contributed to a sharp decline in the Congolese population. The magnitude of the population fall over the period is disputed, with modern estimates ranging from 1.5 million to 13 million. The atrocities have been variously referred to as the Rubber Terror and by some as the Congolese Genocide, though the latter characterization is disputed.
At the Berlin Conference of 1884–1885, the European powers recognized the claims of a supposedly philanthropic organisation run by Leopold II, to most of the Congo Basin region. Leopold had long held ambitions for colonial expansion. The territory under Leopold's control exceeded 2,600,000 km2 (1,000,000 sq mi), more than 85 times the territory of Belgium; amid financial problems, it was directed by a tiny cadre of administrators drawn from across Europe. Initially the quasi-colony proved unprofitable and insufficient, with the state always close to bankruptcy. The boom in demand for natural rubber, which was abundant in the territory, created a radical shift in the 1890s—to facilitate the extraction and export of rubber, all vacant land in the Congo was nationalised, with the majority distributed to private companies as concessions. Some was kept by the state. Between 1891 and 1906, the companies were allowed free rein to exploit the concessions, with the result being that forced labour and violent coercion were used to collect the rubber cheaply and maximise profit. The Free State's military force, the Force Publique, enforced the labour policies. Individual workers who refused to participate in rubber collection could be killed and entire villages razed.
The main direct cause of the population decline was disease, which was exacerbated by the social disruption caused by the atrocities of the Free State. A number of epidemics, notably African sleeping sickness, smallpox, swine influenza and amoebic dysentery, ravaged indigenous populations. In 1901 alone it was estimated that 500,000 Congolese had died from sleeping sickness. Disease, famine and violence combined to reduce the birth-rate while excess deaths rose.
The severing of workers' hands achieved particular international notoriety. These were sometimes cut off by Force Publique soldiers who were made to account for every shot they fired by bringing back the hands of their victims.[vague] These details were recorded by Christian missionaries working in the Congo and caused public outrage when they were made known in the United Kingdom, Belgium, the United States, and elsewhere. An international campaign against the Congo Free State began in 1890 and reached its apogee after 1900 under the leadership of the British activist E. D. Morel. On 15 November 1908,[1] under international pressure, the Government of Belgium annexed the Congo Free State to form the Belgian Congo. It ended many of the systems responsible for the abuses. The size of the population decline during the period is the subject of extensive historiographical debate; there is an open debate as to whether the atrocities constitute genocide. In 2020 King Philippe of Belgium expressed his regret to the Government of Congo for "acts of violence and cruelty" inflicted during the rule of the Congo Free State, but did not explicitly mention Leopold's role. Some activists accused him of not making a full apology.