At the end of the 16th century, the Aussa Sultanate was established in the Denkel lowlands of Eritrea. The polity had come into existence in 1577, when Muhammed Jasa moved his capital from Harar to Aussa (Asaita) with the split of the Adal Sultanate into Aussa and the Sultanate of Harar. At some point after 1672, Aussa declined in conjunction with Imam Umar Din bin Adam's recorded ascension to the throne. In 1734, the Afar leader Kedafu, head of the Mudaito clan, seized power and established the Mudaito Dynasty. This marked the start of a new and more sophisticated polity that would last into the colonial period.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Where was the Aussa Sultanate established?
Denkel lowlands of Eritrea