2negative results that came from cultural encounters in east africa

The negatives of cultural encounters in East Africa can be observed in different periods of time with different new cultures coming in the region. For example, the cultural encounters with the Arab Empire of the Middle Ages, it brought a lot of violence because of the attempt to impose a new religion on the local population, and that was not accepted, so there was bloodshed, as well as slave trade, since the Arabs were seeing the locals as lower race that is only good for physical work.

I'm pretty sure it's c. extremely gradual but not 100% sure though.