This volume explores the legal issues and legal consequences underlying relations between secular and religious authorities in the context of the Christian Church, from its earliest emergence within Roman Palestine as a persecuted minority sect through the period when it became legally recognized within the Roman empire, its many institutional manifestations in the East and West throughout the Middle Ages, the reconfigurations associated with the Reformation and Catholic/Counter-Reformations, the legal and constitutional complications, and the variable consequences of so-called secularization thereafter. The engagement of secular and religious authorities with the law and the question of what the law actually comprised (Roman law, canon law, national laws, state and royal edicts) are addressed. Bringing together the work of a wide range of scholars, this volume deepens our understanding of interactions between the churches and the legal systems in which they existed in the past and continue to exist now.