South Sudan only became independent in 2011, after a long civil war. Up to that point, it had been part of Sudan, but the people voted for independence in a referendum under the peace agreement with the Sudanese Government in Khartoum. However, the country also saw a lot of political instability after independence. South Sudan is bisected by the White Nile. The extreme south-west has a Belgian colonial past, since from 1894 to 1910, it was known as the Lado Enclave and was part of the Republic of the Congo Free State, the private colony of Leopold II.