Introduction Finally, north of the escarpment begins the arid desert where only the esparto grass grows, which is avoided by livestock and even by the camels of the South, forming a barrier 600 km long between the wells of Kseib and the wells of the regions we occupy (4), and this is the desert of the Jawf. Only invasion campaigns descending from the regions of Akkid, the Draa Valley, and the Wadi Dar'a, heading to French West Africa and supplied with water from Kseib, frequent this area. In these parts of the Sahel and Hod regions, tribes of various origins and in varying numbers gather; among the most important is Mashzouf, a Zenaga-Arab tribe that gained its fame through its numbers, influence, and ultimately political dominance. A large number of small, warring factions and Zawiyas or Zenagui (5) of mixed origins, which have now regained their independence, have indeed temporarily gathered around it. Besides Mashzouf, there are tribes of considerable importance, either warring, called Hassani, and therefore of Arab origin, such as Awlad Daoud, Awlad Mubarak, Awlad Muhammad [bin Ahmad], and Awlad al-Nasir, or Zawiya, generally having branches in Mauritania and Azawad, such as Kenta, Al-Igal, Ahl Taleb Mokhtar, Ijmatan, and Al-Kallakama, and Tawahedou, without mentioning the large number of small factions, Zenagui or otherwise. When one undertakes to study the history of the Bidhan tribes in the Sahel and Hod regions one day, there will be no shortage of oral traditions or written documents (small tribal histories, genealogies, annals of the governors of Adrar, and published or unpublished Sudanese histories); we will suffice here with a summary of these sources. The Arab invasions of the Sahara occurred at the end of the 14th century [AD] in an era when the inhabitants of the Sahel consisted of a mixture of Soninke and Zenaga, groups who had embraced Islam; the Zenaga character was increasingly dominant, with the dominance (4) France is meant, and we sometimes refer to it by the name of the French administration or French colonialism, depending on the context. (5) Zenaga and Azanaga are distortions of Sanhaja. Until recently, it was applied to the Idar'ish tribe, as they are descended from a branch of Sanhaja. Their emirate was known as the Emirate of Azanaga or Idar'ish, in contrast to the Hassani emirates. Also from Sanhaja are a number of Zawiya tribes, sometimes called Talaba or Murabitun. The word Azanaga has become applied to a social class in recent times. See Al-Hasswa Al-Bissaniya fi Al-Ansab Al-Hassaniya by Saleh bin Abdul Wahab (manuscript), and Tarikh Idar'ish by Baba bin Al-Sheikh Sidiya (manuscript recently edited by Izzid Bih bin Muhammad Mahmoud), and Tarikh Ibn Khaldun. 8