In the 200s CE, the Persian prophet Mani referred to the “four great powers” of the world. The first three empires are easy to guess: Rome, Persia, and China. Mani’s fourth choice might come as a surprise. He named the Aksumite (or Axumite) Empire of East Africa —
As equal in importance to the other three.
The Aksumites never made any significant attempts to expand outside their own continent (but then again, neither did the Han Chinese). The Aksumite army wasn’t particularly formidable. The empire’s geographical extent was fairly small. Its language never became widely known in the outside world.
Yet Aksum’s wealth was the stuff of legend.