The decline of the Roman Empire saw the classical cities fall into ruin, a process hastened by the Vandals' destructive sweep though North Africa in the 5th century. The region's prosperity had shrunk under Vandal domination, and the old Roman political and social order, disrupted by the Vandals, could not be restored. In outlying areas neglected by the Vandals, the inhabitants had sought the protection of tribal chieftains and, having grown accustomed to their autonomy, resisted re-assimilation into the imperial system.