The European Convention on Human Rights guarantees freedom of education, including opportunities to create and operate faith-based schools. But as European societies become religiously more diverse and "less religious" at the same time, the role of religious schools increasingly is being contested. Serious tensions have emerged between those who ardently support religious schools in various forms and those who oppose them. Given that faith-based schools enjoy basic constitutional guarantees in Europe, the controversy surrounding them often boils down to issues of public financing, degrees of organisational and pedagogical autonomy, and educational practices and management. This introduction to a special issue on controversies surrounding religious schools in a number of Western European countries briefly introduces structural pressures that affect the position of religious schools and sketches the relevant institutional arrangements in the respective countries. We then go on to introduce some of the main concerns that frame the relevant debates. The paper concludes by introducing the various contributions in the special issue.