Isithembu means polygamy and is still a custom in many parts of Africa. Isithembu (also called Sethepu) is the African custom of a man being able to have more than one wife at the same time. There were and are several situations that allow a man to have additional wives. A man may marry again if his current wife or wives cannot have children. He keeps his current wife or wives as divorce is not allowed. She becomes the senior wife, a position of honor. A man may marry again if his current wife or wives have not produced male children. He can marry again if a wife does not want children. In some places, if a man dies, his wife or wives are married to his brother. This way his family is cared for. The Swazi culture says a man should have many wives. Polygamy (Isithembu) is normal for men. Woman should have children, which is normal for them.
- Isithembu as practiced by the Xhosa people is a complex form of polygamy. In this system a man's wives all have positions in the family. Where a man has two wives the family is divided into two branches called "estates". The household (wife, children, members of her family and servants) belonging to his first wife is called the "great house" (indlunkulu). His next wife's household is called the "Right hand house" (ukunene). If he takes a third wife, she and her children are affiliated to the great house. Hers is called a "support house" (iqadi). In some cases the third wife served the first wife as a servant before she was married. Should there be a fourth wife, she and her household are also iqadi and affiliated with the right hand house.
- Fezekile Futhwa, Setho: Afrikan Thought and Belief System (Alberton, South Africa: Nalane ka Fezekile Futhwa, 2011), p. 56
- A. R. Radcliffe-Brown; Cyril Daryll Forde, African systems of kinship and marriage (London; New York: Oxford University Press, 1950), p. 89
- Diane J. Klein, 'Plural Marriage and Community Property Law', Golden Gate University Law Review, Volume 41 | Issue 1 (27 January 2011), pp. 45–47
- "Customary marriages and estates". Ghost Digest. 22 January 2009. Retrieved 23 July 2015.