In the period from 1885 to 1908, many well-documented atrocities were perpetrated in the Congo Free State (today the Democratic Republic of the Congo) which, at the time, was a state under the absolute rule of King Leopold II of the Belgians. These atrocities were particularly associated with the labour policies used to collect natural rubber for export. Together with epidemic disease, famine, and a falling birth rate 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.