The border that separated the newly established nation-states of Syria and Iraq after World War I ran in large parts through desert and steppe land. As a result, it often cut off the circuits followed by Bedouin communities on their seasonal migrations. Yet, as recent border studies scholarship has argued, the introduction of new state borders did not cause a sudden break with previous existing forms of territoriality in the Middle East. The French and British mandatory powers in Syria and Iraq granted the Bedouins legal and political privileges that allowed them to move relatively freely across the shared border. Moreover, in the first half of the 1920s, low state capacities and unclear administrative responsibilities over people and territory provided Bedouin communities with a certain degree of autonomy. In spite of these continuities, by the end of the 1920s, French and British authorities in the Levant had reinforced their border regimes, as demonstrated by the restriction of raiding, new fiscal policies and tighter control of Bedouin mobility; a series of measures that slowly created frontier effects. Notwithstanding this, this paper argues that such policies were not simply determined from above by central state authorities, but rather negotiated on the ground between different state and non-state actors. By looking at the communities belonging to the cross-border Shammar Jarba tribal confederation, it shows first how the question of Bedouin national affiliation became closely entangled with disputes over sovereignty and territorial control between British and French Mandatory powers. The paper then explores how the Bedouins themselves coped and interacted with growing state interference and new state borders. In doing so, it particularly focuses on ‘ordinary’ Bedouins, i.e. community members that did not belong to the sheikhly elite: How did ‘ordinary” Bedouins relations with both state authorities and their own community leadership evolve within this changing context? What strategies did they pursue in the face of the new challenges posed by state borders and the profound political and socio-economic transformations of the period? Although the voices of ‘ordinary’ Bedouins are almost absent in written sources available to historians, the paper seeks to capture their agency by cross-checking of sources from competing national and imperial powers; that is, archival material from the French and British mandate administrations, complemented with German and Arabic sources.