Mali Empire

Under Mansa Musa, the center of writing was in Timbuktu.

An excerpt from the article 21 facts about Mali Empire

Timbuktu is a city in Mali, on the Niger River. Founded in the late 11th and early 12th centuries, for centuries it was the center of intensive trade between Black Africa (sub-Saharan Africa) - the part of the continent south of the Sahara - and Berber and Islamic North Africa, and through it also with Europe.