Hi Clive, thanks for your reply.
The context is:
It started with Europeans invading the West African coast and seizing its inhabitants, in a rather crude and unorganised fashion, for sale on the European market, especially, in the first years, in Portugal and Spain.
The earliest extant record of a slave-catching expedition is that kept by Azurara, leader of a Portuguese venture in 1446.
It is typical of hundreds that were to follow in the generations to come, and we may pause to examine the event as described by its guiding spirit.