In his book Rue des maléfices, Jacques Yonnet considered how one could not get to know the city of Paris without first becoming familiar with ‘sus fantasmas, impregnarse de sus grises, confundirse con la sombra indecisa, ser el hermano silencioso y distante del mendigo, del borracho incluso’ (its ghosts, sinking oneself in its grey colourings, becoming one with its indefinite shadows, being the silent and distant brother of the beggar, even of the drunkard) (Yonnet 1954: 14–15). Yonnet was a journalist and illustrator who regarded visiting the Parisian underworld almost as an occupation in itself. His work invites us to immerse ourselves in the darkest corners of reality during the years of the Nazi occupation of Paris, to go exploring in the depths and shadows of contemporary society, to look squarely at the fear and panic that arose from this society itself.

From the 1990s onwards, work on the history of urban societies has emphasized the multiple and contradictory nature of the processes of modernization before the Second World War. Massive movements of migration with the concomitant processes of industrialization and urbanization, the modernization and expansion of systems of transport and communication, the appearance of new forms of social living and social organization of space all combined to bring about improvements in the life of the individual and ways of collective living. They also brought about adaptations, even full-blown metamorphoses, in the fears, problems and objects of hatred of the past. The process of modernization gave birth to its own dark side, produced by its multifaceted, changeable and unstable nature, able to provoke reactions of both fascination and repugnance. All of these phenomena became more acute from the end of the nineteenth century, and spread to the majority of large cities in the West, above all in the interwar period (Lees and Lees 2007; Whitehand and Carr 2001).

The city of our times, a laboratory for the elaboration of modernity, has become the locus for the contradictions, tensions and resistance to the processes of change in lifestyles and social behaviour, in the exercise of new systems of values and the codification of new forms of social representation.