Across Europe, the emergence of constitutional and democratic nation-states was accompanied by intense conflict between Catholics and anticlerical forces over the place of religion in a modern polity. There had always been intermittent institutional friction between church and state in central and western Europe, but the conflicts that came to a head in the second half of the nineteenth century were of a different kind. They involved processes of mass mobilisation and societal polarisation. They embraced virtually every sphere of social life: schools, universities, the press, marriage and gender relations, burial rites, associational culture, the control of public space, folk memory and the symbols of nationhood. In short, these conflicts were ‘culture wars’, in which the values and collective practices of modern life were at stake.

In Prussia, the largest member state of the German Empire, Otto von Bismarck's government launched a salvo of laws intended to neutralise Catholicism as a political force, triggering a ‘struggle of cultures’ (Kulturkampf) that shaped the contours of German politics and public life for more than a generation. In Italy, the annexation of the Papal States and the city of Rome, and the ‘imprisonment’ of the pope within the walls of the Vatican produced a stand-off between the church and the secular Kingdom of Italy, with far-reaching consequences for Italian political culture. In France, the elite of the Third Republic and the forces of clericalism waged bitter rhetorical battles, to the point where it seemed that secular and Catholic France had become two separate realities.