In the 1870s, just before the onset of the Scramble for Africa, European exploration of the Congo Basin was carried out, first led by Henry Morton Stanley under the sponsorship of Leopold II of Belgium. Leopold formally acquired rights to the Congo territory at the Berlin Conference in 1885 and declared the land his private property, naming it the Congo Free State. During the Free State, his colonial military unit, the ''Force Publique,'' forced the local population to produce rubber. From 1885 to 1908, millions of Congolese people died as a consequence of disease and exploitation. In 1908, Leopold, despite his initial reluctance, ceded to Belgium the so-called Free State, which thus became known as the Belgian Congo.