From the early eighteenth century Dahomey, based at Abomey, and Asante, based at Kumasi, organised warfare in part around the capture of people: campaigns against neighbouring states produced prisoners who were sold at the coast, settled as unfree labour on royal plantations, or held for the annual ceremonies. Dahomey took the coastal ports of Allada and Ouidah in the 1720s and thereafter traded directly with European ships; Asante expanded over the Akan states and northern savanna polities and took tribute in people as well as gold. Both kingdoms continued taking captives after the Atlantic trade was suppressed, redirecting them into domestic slavery and, in Dahomey's case, into palm-oil production. European observers described human sacrifice at Dahomey's annual customs on a large scale, but Robin Law and other historians argue that visitors' numbers were inflated and that the ceremonies were smaller and more political than the accounts suggest. British conquest of Asante (1896-1901) and French conquest of Dahomey (1892-94) ended both systems, and both powers cited slaving and sacrifice as justification for their own conquests.
The kingdoms of Dahomey and Asante raided neighbours for captives, sold most into the Atlantic trade and held or killed the rest
No defensible denominator exists. The raided zone shifted continually over two centuries across the Bight of Benin hinterland, the Volta basin and the northern savanna, and no population counts exist for any of it before the colonial enumerations of the 1900s. Even the raiding states' own populations are guesses: eighteenth-century Dahomey is put at 200,000-350,000 and Asante at anywhere from 1 to 3 million.
There is no defensible aggregate. Deaths in the wars themselves are unrecorded; deaths at Dahomey's annual customs were reported by European visitors in figures from dozens to several hundred a year, which Robin Law regards as unreliable; mortality among captives held or shipped is accounted for in the Atlantic trade entries.
European traders' and missionaries' accounts, and later British and French colonial reports, describe enslavement of captives and ritual executions at Abomey and Kumasi.
Benin, Ghana