Garamantes. The Tibesti are suspected by modern historians to have been part of an unidentified country named Agisymba, and Maternus's expedition may have been part of a broader military campaign by Garamantes against the populace of Agisymba. In the 12th century, the geographer Muhammad al-Idrisi spoke of a "country of Zaghawa negroes", or camel herders, that had converted to Islam. The historian Ibn Khaldun described the Toubou in the 14th century. In the 15th and 16th centuries, Al-Maqrizi and Leo Africanus referred to the "country of the Berdoa", meaning Bardaï, the former associating the Toubou with the Berbers and the latter describing them as Numidian relatives of the Tuareg. The Toubou settled in the Tibesti in several waves. Generally, newcomers either killed or absorbed the previous clans after battles that were often both long-lasting and bloody. The Teda clans, considered indigenous to the area, were first established around Enneri Bardagué. Namely, these clans were the Cerdegua, Zouia, Kossseda (nicknamed yobat or "hunters of well water"), and possibly the Ederguia, although the Ederguia's origin may be Zaghawa and only go back to the 17th century. These clans controlled the palm groves, and made a peace pact with the Tomagra, a nearby clan of camel herders who practiced Ghazw. It was upon the agreement to this pact at the end of the 16th century that power was consolidated under the Derdé, the principal regulator of the clans, whose appointment is always made from the Tomagra clan. There is evidence of early Daza settlements in the Tibesti; however, these early clans—the Goga, Kida, Terbouna and Obokina—were assimilated into later Daza clans, who arrived in the Tibesti between the 15th and 18th centuries, possibly having fled the Kanem-Bornu Empire in the southwest. These later Daza arrivals include the Arna Souinga in the south, Gouboda in the center-west, Tchioda and Dirsina in the west, Torama in the northwest and center-east, and the Derdekichia (literally, "descendants of the chief," the products of a union between an Arna Souinga and an Emmeouia) in the north. The Tibesti then played the role of an impregnable mountain stronghold for the newcomers. Meanwhile, constant migration between the north and southwest of Chad, along with significant mixing of the populations, forged a significant degree of cohesion among the Toubou ethnicities. Periods of territorial expansion in the 10th and 13th centuries and periods of recession in the 15th and 16th centuries likely