[3] They later moved to what is today Mauritania,[4] and from the 16th century onwards, they managed to push back all black peoples southwards to the Senegal Valley river.

For example, the Oulad Delim who trace their origin back to Beni Hassan are the most populous tribe in Western Sahara and consider themselves the cleanest blooded Arabs in the Sahel.

The Ma'qils entered the Maghreb during the wave of emigration of the Arabian tribes in the 11th century, and since then, they were situated in North Africa together with other Bedouin Arab tribes that migrated from the Arabian Peninsula such as the Banu Hilal and the Banu Sulaym, with whom they shared great skill as warriors and a destructive capacity for the nations they attacked.

[15] The Maqil later allied with the Banu Hilal and entered under their protection, which enabled them to wander in the Moroccan desert between the Moulouya River and Tafilalt oases.

[2] The Beni Hassan continued their expansion to the southwest and occupied Sanhaja lands in the 13th century after invading and defeating this Berber confederation with the Lamtuna, Masmuda, Djuddala, Gazula, Banu Warith, Lamta and Tuareg, in a group known as the Baranis in Western Sahara.

[2] The invasion was quick and effective and happened around the year 1250, by the end of the Almohad Caliphate, and also dominated the valleys of the Moulouya, Draa, Sous, as well as the Tafilalt oasis region.

They crossed into the Atlas after taking advantage of the weakening Marinid Sultanate around 1460 and then they dominated the Haouz region of Marrakesh by the beginning of the 16th century.

Other groups migrated north through Tafilalt to Fez or up the Sebou and Bou Regreg rivers, where some settled south of Rabat.

[17] The Hassanis were represented in the Haouz of Marrakech by the Rahamna, who were brought north to respond to the military needs of the Saadian Sultanate in the early 16th century.

[17] Historical accounts report that these Hassani communities enriched themselves by collecting tolls from trade caravans and extorting farming and herding villages settled in the oases.

They were accused of subjecting these territories to two centuries of looting and intermittent wars, but at the same time they point out that their families settled in the same towns that they attacked and subjugated.

[18][12] This took place during the Char Bouba War from 1644 to 1674, which after decades of confrontations ended up completely Arabizing the native Berber population, destroying their language and culture and giving rise to the contemporary Sahrawi people.

[20] In 1674, the Beni Hassan defeated the Marabout Berbers, and after achieving political and military hegemony in the area, they founded the emirates of Trarza, Brakna, Tagant, Adrar and Hodh.