and 1912 for a program to contain sleeping sickness in the "great uninfected triangle" of the Uele. The military campaign against Sasa, the powerful leader of the Azande, exposed the true extent of the disease. It was found that sleeping sickness was widespread in the north of Uele District. The district was to have been opened to free trade in July 1912, and flooded by mineral prospectors, traders and their porters. Belgian Congo The Congo Free State was annexed by Belgium as the Belgian Congo in 1908. On 1 July 1910 a court of first instance was established at Niangara to serve Uele District, one of seven in the colony. The Uele District was divided into Bas-Uele (Lower Uele) and Haut-Uele (Upper Uele) by an arrêté royal of 28 March 1912, which divided the Congo into 22 districts. In a major reform in 1914 these were incorporated into the Orientale Province. In the reorganization of 1933 Bas-Uele and Haut-Uele were reunited into Uele District, now part of the Stanleyville Province, with some territory to the east transferred to the Kibali-Ituri District. Stanleyville Province was renamed Orientale/Oost Province in 1947. During the colonial era a railway was constructed through the region from east to west, on which the agricultural road network converged. The railway carried products from Uele and Ituri to Bumba, from where it was taken to Léopoldville, Boma, and on to Europe. In 1947 Uele District had its headquarters in Buta. The territories were Bondo, Ango, Dungu, Manbetu (headquarters in Paulis), Buta, Aketi, Poko and Niangara. The estimated total populations was 795,721. In 1956 the population was: The population was concentrated along the axis from Paulis to Aketi. A 1955–1957 map showed that Uele District had once more been divided into Bas-Uele and Haut-Uele. Post-independence In 1962 Orientale Province was broken up into Kibali-Ituri, Uélé and Haut-Congo provinces. Uele had its capital in Isiro. The heads of Uélé Province were: Orientale Province was reconstituted in 1966. As of 2014 Bas-Uele had the lowest population density in the country, with 5 or 6 people per km2, while Haut-Uele had 13 people per km2. In 2015 Orientale was broken into the province into the provinces of Bas-Uélé, Haut-Uélé, Ituri and Tshopo. Maps See also Districts of the Congo Free State Districts of the Belgian Congo Notes References Sources / http://www.kaowarsom.be/en/online_maps Districts of the Congo Free State Districts of the Belgian Congo