How negros sold other negros and started the slave trade, slave kingdoms of Afrika part1

How Negroïds sold other negroïds and started the slave trade, slave kingdoms of Afrika ,part1,we wuz kangz,slave trade,Afrika,black people,negro,savages,barbarians,dahomey,mali,etheopia,Africans sold Africans,
Black Afrikans started the slave trade and became rich from it,
It is Afrikan custom to enslave the tribe , you just attacked , raped and pillaged.