When the Rustamids collapsed and the Fāṭimids occupied their capital Ṭāhart in northwestern Algeria in 909 CE, the Ibāḍī Berbers sought refuge in the southern oasis of Sadrāta, whence they moved to the Mzāb and founded Ibāḍī townships between 1011 and 1053. In the same period, the Banū Hilāl arrived in present-day Algeria through the coast and desert with titles to property (iqtā‘). After they populated the region side by side, shaking hands in some matters and denying truces in others, their respective historical memories became contingent on different interpretations of a single migration and its motivation. The Banū Hilāl were framed as proponents of dissolution and destruction of state– a narrative informed by Fāṭimid sources then later affirmed by medieval scholars like Ibn Khaldūn. Situating the Banū Hilāl myth has not only been a matter of assessing the nature of early Arabization of North Africa but has also directly shaped the historiography of a forgotten oasis city whose oppositional narratives project back onto larger questions of indigeneity and sense of belonging that bear great stakes. The history of the Sha‘ānba, descendants of these Banū Hilāl in the Mzāb, mirrors the same colonial and post-colonial debates. A web of complex relationships between the nomadic and sedentary, Arabophone and Berberophone, that are dually influx and interconnected, was lost in colonial ethnography. New questions based on this case study may lead us to fresh reflections on a myth that has ceased to regenerate: What are the lasting effects of the Banū Hilāl myth within the historiography of the Mzāb? How have the descendants of the Banū Hilāl in the Mzāb asserted their own narrative?