Historical Dictionaries of Africa
There is generally a dictionary for each country in Searchworks.  Contents include name changes, maps, chronology, history, important people. Some examples -

Historical Dictionary of Ancient Egypt 

Historical Dictionary of Ancient and Medieval Nubia

Historical Dictionary of Eritrea

Historical Dictionary of Ethiopia

Historical Dictionary of Ghana

Historical Dictionary of Kenya

Historical Dictionary of Namibia

 Historical Dictionary of Nigeria

 Historical Dictionary of the Sudan

Historical Dictionary of Uganda
 

A&AePortal
Subscrption required. Ebooks on art and architectural history published by The Art Institute of Chicago, The MIT Press, Yale University Press, Harvard Art Museums, and the Yale University Art Gallery. Includes an African section. Can search for images in the books. https://searchworks.stanford.edu/view/12697374

• One of the ebooks in the database is this publication -
  Snowden Jr., Frank M. "3. Iconographical Evidence on the Black Populations in Greco-Roman Antiquity." The Image of the Black in Western Art, Volume I: From the Pharaohs to the Fall of the Roman Empire, edited by David Bindman and Henry Louis Gates Jr., Harvard University Press, 2010. A&AePortal, https://doi.org/10.37862/aaeportal.00137.007

African Archaeology Information Online - Stanford Library Guide

• Online primary sources, African university resources, academic journals online.