Answer:
People who have answered so far have no idea what they are talking about. Islam had started spreading into Africa even during the time of prophet Muhammad,and except for North Africa, Muslim armies never ventured south into the Sub-Saharan region. Islam grew as a result of trade and migration of African Muslims into the south.
Explanation:
It depends on how long he served, overseas or not, and if he was a specialist in one area.
The migration mostly lead the population of the world to grow and even spread. it lead people's life style to be more composite. it even lets other society's be born
