“Towards the end of the 19th century, the Bongo people were a powerful tribe. They numbered 100,000 and occupied a region of southern Sudan, on a large plain to the west of the White Nile. The Islamic slave trade dramatically reduced their population to 5,000 by the 1920s, although they have slightly grown in number since then. Bongo elders hold political authority and their economy is mainly based on farming sorghum and millet.”

Source:
Baquart, Jean-Baptiste. The Tribal Arts of Africa. New York: Thames and Hudson Inc. 1998. Print.