The reason for this question is because I was looking at the words for "white person" in various Bantu languages. It turns out a large number of Bantu languages share a word for "white person", but the word couldn't have spread after colonialism; it's much older than that. I would estimate that the word is at least 1000 years old. It has a few variations, suggesting that it was borrowed across languages long ago, after the Bantu languages had already split up from their common ancestor. Here is a rough map I made.
So in order to better understand the history of this word, I'm hoping to get an idea of realistically how long ago Bantu peoples (or any sub-Sarahan Africans) could have had contact with white people.
Not to discourage any further answers but you'll probably like /u/cleopatra_philopater's answer to To what extent were the Romans in contact with native African tribes and kingdoms? How deeply did Rome explore, but not necessarily conquer or colonize, the African continent? from the FAQ on Africa.
