The Empire of Mali flourished between 1200 & 1600 CE, in sub-Saharan West Africa. At one point the Empire was so wealthy that when its ruler, Mansa Musa, travelled through Egypt on his Hajj he reduced the value of gold in Egypt with the amount he gave away. Discussing the empire on In Our Time were Amira Bennison (University of Cambridge), Marie Rodet (SOAS) and Kevin MacDonald (University College, London).
The Mamluks were a slave army that went on to rule Egypt (and Egypt's empire) for around 300 years between the mid 13th Century & the early 16th Century AD. Although we call it a dynasty the position of sultan was generally not hereditary during this period, and before one could be a sultan one needed to have been a slave. The three experts who discussed it on In Our Time were Amira Bennison (University of Cambridge), Robert Irwin (SOAS, University of London) and Doris Behrens-Abouseif (SOAS, University of London).