Axum Empire

The ancient Axum Empire existed in what is now Ethiopia (the name "Ethiopia" was used as early as the 4th century), Eritrea, Sudan, Somalia, and Yemen from 880 BC to 825.

An excerpt from the article 20 facts about Axum Empire
It was an advanced civilization that surpassed the development of ancient Europe. It can even be assumed that its knowledge was more extensive than that of the Europeans in the 15th century.