Military state carved out of the Lake Chad basin by the Sudanese warlord Rabih az-Zubayr, who deposed the al-Kanemi dynasty of Kanem-Bornu in 1893 and ruled it and conquered Bagirmi as a highly centralized, garrison-based military dictatorship from his capital at Dikwa.
Rabih was defeated and killed by a French colonial expeditionary force under Lamy and Gentil at the Battle of Kousséri on 22 April 1900; the al-Kanemi dynasty was briefly restored under French/British/German colonial suzerainty as the region was partitioned, and his death opened the way for French colonization of Chad.
The standard English-language biography/history of Rabih az-Zubayr and his central African military state, verified via Open Library.