Kasai-Oriental is one of the 26 provinces of the Democratic Republic of the Congo. Specified under Article 2 of the country's 2006 Constitution, the new province was finally created in 2015 from Tshilenge District and the independently administered city of Mbuji-Mayi, both part of the larger, pre-2015 Kasai-Oriental province. The new province's territory corresponds to the historic Sud-Kasaï province that existed the early period of post-colonial Democratic Republic of the Congo between 1963 and 1966.
The capital of the province is Mbuji-Mayi, formerly Bakwanga, on the Sankuru river.
Kasai-Oriental is inhabited by members of the Luba tribe.
Congo obtained independence from Belgium in 1960. Friction with Congo's other ethnic groups and encouragement by Belgian corporations hoping to keep their mining concessions led to the secession of the province of South Kasai as a separate state headed by Albert Kalonji.
After being repulsed, the Congo occupied the province in September 1961. Several thousand people were killed during the "pacification" of South Kasai, which lasted through the spring of 1962.
The population of Mbuji-Mayi grew rapidly with the immigration of Luba people from other parts of the country.
The region in which Mbuji-Mayi is situated annually produces one-tenth in weight of the world's industrial diamonds, with mining managed by the Société Minière de Bakwanga. This is the largest accumulation of diamonds in the world, more concentrated than those at Kimberley, South Africa. Mbuji-Mayi handles most of the industrial diamonds produced in the Congo.
The province consists of the following five territories:Kabeya-Kamwanga
French is the official language. Tshiluba is one of the four national languages of the Democratic Republic of the Congo. Tshiluba is spoken by about 6.3 million people in the Kasai-Oriental, Kasai-Occidental and Lulua provinces.