Most Central Sudanic speakers reside in Chad. The Bulala—who live near Lake Fitri—are the northernmost of the Central Sudanic speakers, and the Sara are the southernmost; the Barma—who are found near the Bahr Erguig—are intermediate. From approximately A . D . 1000 to 1900, Central Sudanic history was characterized by a regional political economy consisting of different types of societies performing different roles in the trans-Saharan trade, which was largely in slaves. In the north were desert specialists, societies like that of the Tubu that assured the travel of caravans across the desert. In the center were states—Muslim emirates like that of the Bagirmi (in which the Barma were preeminent)—that warred to acquire and sell slaves. In the south were cereal producers, societies like that of the Sara that were the major reservoirs of slaves.
People in the precolonial states called those they raided "Kirdi," which generally meant any non-Muslim, and hence enslavable, person. The Bagirmi specialized in raiding Kirdi Sara during the nineteenth century. In the early twentieth century the Sara were incorporated into French Equatorial Africa. The southern portion of Chad was considered by the French "1e Tchad utile," and it was here that administrators concentrated their efforts. The impact of colonization thus fell squarely upon the Sara. Their society was transformed by the introduction of taxes, paid in cash; of forced labor, especially on the Congo-Ocean Railroad; of obligatory cotton production; and of service in the French military, especially during World War IL By independence in 1960, the Sara were better educated and had greater experience with French political institutions than did the northern populations that had formerly raided them.