Sultanate of Dahlak
The Sultanate of Dahlak was an Arab Muslim sultanate founded in 702 on Dahlak Kebir Island.
The coastal area until the late 7th century was dominated by the Aksumite Empire, who were well connected into the Indian Ocean and Red Sea trade network from their great market city of Adulis (al-Zula, still called Zula today). By the year 700 the Aksumite Empire collapsed, Adulis had been abandoned, and the coast had been overrun with pirates. In 702, pirates from the coast and Dahlak Islands attacked Jeddah, prompting a strong response from the Ummayad Caliphate. The Ummayads conquered and occupied the region, though showed little interest in East Africa beyond ending piracy and used the Dahlak Islands primary as a place of exile for those falling out of favor with the Ummayad (and later Abbasid) court. The Caliphate saw no value in the Eritrean coast and delegated their rule to nearby Beja tribes, creating the Sultanate of Qata.
When the Abbasid Caliphate de facto collapsed in late 9th century into a hundred virtually independent (then later completely independent) states, Dahlak ended up within the chaotic Yemeni political orbit, until the Dahlak Islands established itself as an independent entity in the 11th century.
The Dahlak Islands continued on until the 16th century when the Portuguese took exception to the economic competition posed by the Sultanate of Dahlak, and literally destroyed the sultanate by naval bombardment in 1526. The Ottoman Empire occupied the islands in 1557 and they became part of the Habesh Eyalet.