This is a herdsman from what is now the Northwest African country of Algeria during Roman times. His look is based on one of the subjects of a Roman mosaic exhibited at the Setif Museum in Djemila, which depicts a handful of dark-skinned African captives being herded alongside exotic animals and Roman citizens. Where on the continent the captives would have come from seems to be anyone’s guess, but mine is that they would have been natives from the area of Algeria beyond Roman imperial control. The observer may notice in the mosaic that most of these Africans are wearing Romanesque dress which suggests a degree of cultural influence from Rome or other Mediterranean civilizations.
You can check out the original mosaic here: https://www.flickr.com/photos/tobeyfootsteps/43935080911