Speaking about African empires in general, like the Americas and Pacific Islands, Africa was cut off from the warfare and trade routes that stretched from central Europe to China for thousands of years and allowed for the massive exchange of ideas and technology that allowed Eurasia in general to develop so much scientifically.
Nevertheless, some of the North African places which were in contact with Eurasia, such as the Ancient Egyptians and the Moors achieved impressive scientific and cultural accomplishments.
In addition, Africa has had several major kingdoms in various regions. One of the most notable is the Abyssinian empire, which lasted for several centuries, decisively defeating an Italian invasion in the Battle of Adwa as recently as 1896.