By the sixteenth century, one of the foundations of Kongo belief systems was the division of the universe into two parallel realms: the living and the dead. The threshold between them is conceived as a body of water referred to, like the Congo River, as nzadi. In that context existence is a cyclical journey that requires movement across this continuum. The realm of the living is characterized as black; that of the ancestors, or mpemba, as white. White kaolin, or chalk, drawn from riverbeds is emblematic of contact with the ancestors and purity, while red denotes a transitional state of being or transformation. Those in the Kingdom of Kongo who converted to Catholicism adapted its precepts to this indigenous worldview.
In Kongo society, a finite amount of power is believed to exist and is allocated through mystical transactions. An nganga (pl. banganga) is a ritual specialist enlisted to defend his clients against mystical attacks. He activates a specific spiritual force to identify and punish those responsible for afflictions ranging from misfortune and sickness to death. That force is invoked through an nkisi (pl. minkisi)—a complex of songs, ritual actions, and physical matter. The material component consists of medicines (bilongo) made of animal, vegetable, and mineral matter selected for their metaphorical significance and ability to attract the spiritual force appropriate for the resolution of a particular complaint. This mixture is housed in a portable shrine that might be a simple clay vessel or a customized figurative wood container made by a professional carver.
The banganga responsible for the development of new varieties of minkisi that were effective in addressing social needs were amply remunerated. Despite this premium placed on innovation, in the West their creations have been characterized as static. While European visitors commented on Kongo religious sculptures as early as 1491, they did not describe them with any specificity and no known examples were collected before the nineteenth century. During the second half of the nineteenth century, European traders and colonial officials acquired thousands of examples, but information relating to the original use of specific works was rarely recorded.
