Please find some very interesting websites linked on this page containing historic maps and facts about the African continent.
I am not befriended or related to any of the authors listed below.
http://www.timemaps.com/history/africa-3500BC
This is my absolut favourite website - You'll find an interactive map of African empires from 3500BC until today. By clicking on the map you jump a few hundred years ahead and you can see how the empires expand and shrink. Very well done!!
www.kcl.ac.uk/sspp/departments/geography/people/academic/drake/Research
This website of the King's College London presents very interesting research about the history of the Sahara desert, including maps of ancient waters and vegetation.
https://tracingafricanroots.wordpress.com
This is one of the most amazing websites I have come across in my research. Please make sure you are checking it out, it is always up to date. You've got interesting sections about Ancestry DNA, DNA Studies, Ethnic and Regional Origins, an amazing set of Maps explaining wide parts of African history. The collection of maps is absolutely outstanding and you can spend hours just learning from them.