French colonists referred to the Southern part of this country as "Useful" this country, and one empire centered in this country was chronicled in the  Girgam. That empire converted to Islam under Emperor Hummay. That conversion caused the (*)  Zaghawa people to flee this country. One former leader 
French colonists referred to the Southern part of this country as "Useful" this country, and one empire centered in this country was chronicled in the  Girgam. That empire converted to Islam under Emperor Hummay. That conversion caused the (*)  Zaghawa people to flee this country. One former leader of this country was convicted of Crimes against Humanity by the Extraordinary African Chambers in May 2016. That leader won a war centered around the cities of Faya-Largeau and Ouadi Doum in the Toyota War. This country's Borkou-Ennedi-Tibesti region is adjacent to the disputed region that provoked that war. For ten points, name this country formerly ruled by Hissene Habre, whose border with Nigeria runs through its namesake lake.
French colonists referred to the Southern part of this country as "Useful" this country, and one empire centered in this country was chronicled in the  Girgam.
Chad