The different theoretical notions and practices of the relations between the state and religious communities in early modern Europe constitute one of the most interesting problems in historiography. Moving away from a simple «toleration» versus «non-toleration» dichotomy, the author sets out to analyse the inter-confessional relations in selected European territories in a «longue duree» perspective, between Reformation and Enlightenment. Outlining the relations between the state and the different Churches (confessions) in the Polish-Lithuanian Commonwealth, the Holy Roman Empire of Germany, and the Northern Netherlands serves to highlight the specificity of Northern Netherlands serves to highlight the specificity of «free» (non-absolutist) composite states, where the particularly complex process of defining the raison d'etat determined the level of religious toleration that was politically feasible and socially acceptable.«Kriegseisen provides the English-speaking world with a well-documented political history of the Protestant Reformation in Poland-Lithuania. His monograph is a resource for complexity and nuances of various Protestant streams in their church-state relations.» (Vilius Rudra Dundzila, Tijdschrift voor Geschiedenis 1/2018) «Students of early modern central European religious history will no doubt find this work of value [...].» (Christine Kooi, Journal of Ecclesiastical History 68/4 2017)