The kingdom of Dahomey rose as slaving in its region grew, and the overlap has made it a standard case study of what the traffic did to African societies. Law reviews how historians have handled that story, trying to establish how the Dahomian state and its own slaving were actually connected.

One long-running view holds that Dahomey's rulers originally meant to bring the traffic to an end. Law considers that claim and refutes it. He turns instead to the kingdom's militaristic character, which is best understood, he suggests, as a consequence of warfare intensified by overseas demand for prisoners of war.

A third interpretation reads Dahomey's political centralization as a constructive answer to the disorder that raiding for captives brought with it. Law examines that position too, and endorses part of it.