My research began with Henry Mayhew and London Labour and the London Poor. I then moved on to study the history of medicine and war. My first monograph, devoted to the history of Paris during the sieges, was consistent with my earlier work on urban representations and invited a reflection on the history of modernity and the city. Through my interdisciplinary work as a teacher we embarked on a collective venture on the Arcades Project work of Walter Benjamin. Our project, published as Benjamin's Arcades an Unguided Tour represented the congruence of our research interests in a given moment in the history of ideas.
A salient feature of this work, namely the history of humanitarianism has now been my central concern since 1999. It is a broad theme covering the nexus of humanitarianism and war over a long period of at least 130 years, and for the later period médecins sans frontières.