Which were the cultural borders of the Dutch-speaking Catholicism between 1830 and the end of the nineteenth century? To what extent were the Netherlands situated within the ‘mental space’ of the Flemish Catholics and, vice versa, how much was Flanders a part of the cultural horizons of the Dutch Catholics? Or put differently: what was the answer of the nineteenth-century Catholics to the burning question whether the Netherlands and Flanders share the same language and culture? Starting point of these research questions is the observation, already emphasised in the existing literature, that the Dutch and the Flemish cultures started to distinguish themselves in the course of the nineteenth century while undergoing a process of (re)definition of the mutual ‘cultural borders’. In Dagnino’s work, the position of the Catholic culture is scrutinised within this general scope. Drawing on three Dutch (J.G. le Sage ten Broek, J.A. Alberdingk Thijm, the ultramontane triad Schaepman-Brouwers-Nuyens) and three Flemish/Belgian case studies (J.B. David and the ‘spelling war’, Guido Gezelle and the Western-Flemish ‘particularism’, the Gothic Revival group Gilde de Saint Thomas et Saint Luc), Dagnino focuses on processes of reciprocal conceptualisation within the Low Countries in the fields of language, literature, history, art and architecture, but also contributes to a better understanding of the cultural and social emancipation of both the Catholic part of the Dutch population and of the Flemish Movement within the context of the Belgian state.