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After the decline of Aksum, the Eritrean highlands were under the domain of Bahr Negash ruled by the Bahr Negus. The area was then known as Ma'ikele Bahr ("between the seas/rivers," i.e. the land between the Red Sea and the Mereb river). It was later renamed under Emperor Zara Yaqob as the domain of the Bahr Negash, the Medri Bahri ("Sea land" in Tingrinya, although it included some areas like Shire on the other side of the Mereb, today in Ethiopia). With its capital at Debarwa, the state's main provinces were Hamasien, Serae and Akele Guzai.

What were the main provinces of Medri Bahri?
Hamasien, Serae and Akele Guzai