This book provides a significant rereading of political and ecclesiastical developments during the English Revolution, by integrating them into broader European discussions about Christianity and civil society. Sarah Mortimer reveals the extent to which these discussions were shaped by the writing of the Socinians, an extremely influential group of heterodox writers. She provides the first treatment of Socinianism in England for over fifty years, demonstrating the interplay between theological ideas and political events in this period as well as the strong intellectual connections between England and Europe. Royalists used Socinian ideas to defend royal authority and the episcopal Church of England from both Parliamentarians and Thomas Hobbes. But Socinianism was also vigorously denounced and, after the Civil Wars, this attack on Socinianism was central to efforts to build a church under Cromwell and to provide toleration. The final chapters provide a new account of the religious settlement of the 1650s. "Mortimer’s study offers crucial insight into this previously ill-understood aspect of English history, shedding light on [Socinian] influence during the mid 17th century … there is much to be learnt from this impressive study about a whole range of interrelated debates that were of central importance to the religious and political developments of the period." Richard Bell, Reviews in History "… a valuable work …" Ted Vallance, The Journal of Interdisciplinary History "Sarah Mortimer's examination of Socinian thought in England during the Revolution is long overdue." Melissa M. Gladwell, Sixteenth Century Journal "Eighteenth-century English Socinianism is deserving of further study and the way will be illuminated by Mortimer's very fine book." Jeffrey R. Wigelsworth, Canadian Journal of History "All students of seventeenth-century English theology, history, and politics are indebted to Sarah Mortimer for a richly contextualized account of the widespread reception and utilization of a variety of Socinian ideas." Martyn Cowan, Churchman Examines the reception of Socinian ideas in England, providing a rereading of political and ecclesiastical developments during the English Revolution. Sarah Mortimer is a Tutor at Christ Church, Oxford.