This article proposes a historiographical and conceptual analysis of ordinary practices of politics and their centrality in the elaboration of the idea of the common, considering the works of historians and those of political scientists. Following different paths, the two disciplines have pursued avenues of enquiry that seem to be converging, even though no formal connections have yet been made. On the basis of these findings and the analysis of recent works, this article proposes definitions and principles for studying these ordinary political practices, and examines the sources at our disposal, the forms of action and discourse they reveal, the content and the meaning of these practices, and their influence on the construction of the political order by public authority. This introduction reflects on the theoretical principles that underpin the articles in this issue, and questions in particular definitions of the ordinary, notions of the common, of the world, of proximity or fluid conjunctures that have structured our collective reflections.