In 828-829, Idris II died in Volubilis at the age of thirty-six, leaving behind twelve sons. Mohammed succeeded him and divided the kingdom with seven of his brothers, while the remaining four were too young to hold command. Abdallah Ibn Idris received the Sous el-Aqsa in the division, encompassing the Sous valley with Igli as its capital.
Due to the independence or insubordination of the Lamta, who controlled the main western route from north to south, Abdallah ibn Idris, king of the Sous, was likely deprived of communication with the Saharan side of the Anti-Atlas, its oases, its productions, and its trans-Saharan trade. This inability to use the coastal plains passage possibly led him to establish the settlement of Tamdoult during the first half of the 9th century. Tamdoult was located six days’ march south of his capital Igli, at the foot of Jbel Bani, near the pass of Aqqa. This pass served as the main Saharan outlet of the central Anti-Atlas passage via the Igherm pass and the Oued Aqqa—a traditional route connecting the Sous valley with the central Bani oases, notably Aqqa and, formerly, Tamdoult.
By the end of the 10th century, Tamdoult was equipped with a citadel and belonged to a descendant of Idris, Yahya ibn Idris. It was situated among the villages of the Banou Dara, likely comprising black or negroid people, similar to those known today in eastern Dra under analogous names: Aït Dra in Berber, Draoua in Arabic. Most of the region’s inhabitants were Berbers, specifically Banou Targa (Touareg), who were considered white, as opposed to the black or negroid Banou Dara. In the vicinity of Tamdoult, deposits of gold and silver were found on the ground’s surface, reportedly so abundant that the winds could disperse them. It is possible that Tizgui l-Haratine, noted in the 10th century, was part of Tamdoult and Yahya ibn Idris’s domain in the 9th century. The qsar and palm grove of this name were located at a pass in the Bani, at Foumm Aït Ouabelli, halfway between Aqqa and Foumm el-Hassane; they were also known as Tizgui Issouqqiyene and Tizgui Irirhene.
During this same 9th century, Tamdoult and the villages of the Banou Dara were also considered to be under the influence of Sijilmassa, under the reign of Midrar (823-867), the eponym of its dynasty. Although Sijilmassa seemed somewhat distant (440 kilometers as the crow flies) to exert effective or lasting sovereignty, Igli, the capital of Sous, was only 130 kilometers away, though reachable by more difficult mountain paths.
The possession of Tamdoult in the south of the Anti-Atlas and Neffiss in the north of the Western High Atlas, along with the passes leading there, would have conferred significant power to the king of Sous established in Igli, located approximately halfway between the two cities. By the end of the 9th century, the Idrissids resided in Igli, Tamdoult, and Neffiss. In Igli, it was the Banou Abdallah ibn Idris; in Tamdoult, Yahya ibn Idris; and in Neffiss, a grandson of Abdallah ibn Idris ruled over the territory granted to his grandfather during the kingdom’s division among the sons of Idris II. Ancient authors do not provide further information on the fate of these places until the Almoravids seized them in the mid-11th century. Consequently, the duration of Idrissid control over them remains unknown.