"Under Leopold II's administration, the Congo Free State became the site of one of the most infamous international scandals of the turn of the twentieth century. The report of the British Consul Roger Casement led to the arrest and punishment of white officials who had been responsible for cold-blooded killings during a rubber-collecting expedition in 1903, including one Belgian national for causing the shooting of at least 122 Congolese natives. Estimates of the total death toll vary considerably. In the absence of a census, the first was made in 1924, it is even more difficult to quantify the population loss of the period. Roger Casement's famous 1904 report estimated ten million people. According to Casement's report, indiscriminate 'war,' starvation, reduction of births and tropical diseases caused the country's depopulation."
The Congo Free State included all of what is now the Democratic Republic of the Congo, which is our "History of" country today.