[4] The Seven Kingdoms were also called Momboares in the 17th-century text of the Portuguese Jesuit priest, Mateus Cardoso, which offers an extensive description of the region.
[5] Cardoso noted that the region was famous in his day for the large amount of cloth that it produced, some of which was exported to the Portuguese colonial city of Luanda, Angola.
Reports of the early 17th century suggest that the Seven Kingdoms exported as much as 100,000 meters of cloth annually to that market alone, suggesting that its total production must have been several times higher, putting in on a par with other major textile centers in the world, including areas of equivalent size in Europe and India.
Research by Jan Vansina proposes that the origin of larger political structures began within the northern reaches of the kingdom at about this time, on linguistic evidence.
Graziano Saccardo, Congo e Angola con la storia del antica missione dei cappuccini, (3 vols, Milan, 1982–83)