It's just like white history, south asian history, east asian history, etc ie the story of temporarily dominant nations, tribes or families raping, pillaging, enslaving, murdering those who were not as strong in that moment. The north africans did it to the europeans for 300 years, the mongols did it to their neighbors, the zulus did it, the black africans did it to the pygmies, and so on around the world forever. Only once in history did a dominant civilisation try to put an end to slavery at its own cost that t was the British