Arabization of The Mujahideen (13th and 14th Century)
In the time of the Almoravids professional warriors had fought as 'mujahideen' in their holy war. Just like the people who had united in zawyas, the mujahideen began to form tribes based on their specific occupation. This development was accelerated by the arrival of Maqil Arab tribes. In the 13th and 14th century, these tribes migrated westwards along the northern border of the Sahara to settle in the Fezzan (Libya), Ifriqiya (Tunisia), Tlemcen (Algeria), Jebel Saghro (Morocco), and Saguia el-Hamra, (Western Sahara). When the Maqil Arabs arrived in the western part of the Sahara the muyahidin were most prone to Arabization. While the zawiya tribes retained many of their Berber characteristics, the warrior tribes tried to 'Arabize' as much as possible. They constructed genealogies of the ancestors of their tribes, connecting them to members of the Maqil and Arabizing their ethnonyms. Thus the Nyarzig, for instance, became the Ouled Rizg. However, this right to call yourself 'Arab' was only restricted to some tribes. These tribes, the Banu Hassan or simply Hassan, were to function as a warrior class in the next centuries.
The Arabized Berber tribes controlled key oasis settlements of the Sahara and played an important role in the trans-Saharan slave trade. They already used to impose heavy taxation on any traffic through their lands, while also furnishing protection, supplies, and camels. When trans-Saharan trade intensified, they developed departure and arrival centers with slave depots and intermediary secure caravan stops. In these centers, they oversaw the traffic from sub-Saharan regions to Egypt, Tunisia, Algeria and Morocco. Timbuktu (Mali) was a central crossroad to all four routes. Ouadane, Idjil (near Atar), Azougui, Araouane, Taoudenni and later Tindouf were important stopping-places. At the same time the number of slaves kept in Western Sahara itself increased drastically.
The Maqil tribes, who entered the domains of the Sanhaja Berber tribe, sometimes intermarried with the Berber population. The Arabo-Berber people of the region is now known as Saharawi. An exonym sometimes used to describe the Banu Hassan tribes of present-day of the region was Moors. The Arabic dialect, Hassaniya became the dominant mother-tongue of the Western Sahara and Mauritania. Berber vocabulary and cultural traits remain common, despite the fact that many Saharawi people today claim Arab ancestry.
Read more about this topic: History Of Western Sahara