This chapter offers a historical and theoretical background to the practice of walling. Based on linguistic and archaeological data it argues that the probable origins of the practice lie in entrapping and not protection, exclusion, or the blocking of movement: the entrapping of animals by barriers or weirs in the Palaeolithic, and the entrapping of animal-form trickster-demons in the first megalithic sanctuary of Göbekli Tepe. The extension of walling to closing settlements was as much associated with the dream-hope of complete protection as the gaining of control over the population enclosed, starting from Jericho, also connected to rituals of sacrifice, while the void thus generated inside was bound to generate warfare, conquests, and globalising empire-building toward the outside. The specific feature of modern walling is to generalise the setting up of abstract limits and boundaries into a universal practice, animating the permanent oscillation between searches for absolute freedom and absolute protection, underlying the shifts between liberal, socialist and totalitarian political movements, purported alternatives, yet entrapped in the same walling logic, representing successive stages in a series of dysfunctional linear transformations, away from what is given in nature.