“What Has the Emperor to Do with the Church?” Non-Nicenes and Constantinian Retractions

This paper reexamines the entanglement of church and state by returning to the earliest and most persistent critics of imperial intervention in Christian affairs: the Donatists. Using Donatus’s famous question—“What has the emperor to do with the church?”—as a guiding thread, the study traces a counter-tradition of resistance to coercive Constantinianism from the fourth century through the Reformation and into modern Baptist Landmarkism. After reviewing Constantine’s involvement at Nicaea and his earlier engagement with the Donatist controversy, the paper situates Donatism within a broader African lineage that includes Tertullian and Lactantius, both of whom articulated early notions of religious liberty. It then follows the afterlives of Donatist ideas as later dissenting movements, from Anabaptists to English Separatists and Landmark Baptists, were labelled “Donatist” for opposing state control of the church. Finally, the paper proposes a reconsideration of Augustine’s political theology—especially in light of his own ambivalence and the later “Augustinian” resistance to imperial interference—to suggest constructive resources for contemporary Christians seeking to affirm both conciliar orthodoxy and robust religious freedom. The study argues that the Christian defense of liberty of conscience long predates modernity and remains essential for the church’s public witness today.