The vast Luba territory, comprising the entire southeastern part of the DRC, as far as Tanganyika and Lake Mweru, is uniform as regards language and culture, but racially mixed. The depiction of the female form in Luba art is sometimes a reference to a particular named woman in Luba history, such as the mother of a chief or king, or a wife who was sent to establish a new domain in an outlying territory. Designed to forecast future events, the bowl bearer – known as a mboko (the name for the sacred vessel held by the figure) – is a vivid example of how knowledge and divination are visualized in Luba culture. Luba bowl figures commemorate the first mythical Luba diviner, Mijibu wa Kalenga, and were primarily the preserve of royal diviners who used them as oracles. More recently, such works have also been commissioned by rulers for use as containers filled with sacred chalk, an empowering material associated with purity, renewal, and the spirit world.