This book is the latest contribution to the Oxford Studies in Historical Theology. Its subject matter is the failed attempt of Cromwellian Protestants, as an embattled minority, to provide security for English settlers and to revenge the 1641 rebellion. It also details the feuds that broke out between Protestants in Ireland and the instability that they produced. In the clash over theology Crawford Gribben has identified five main themes: conversion, baptism, church government, miraculous signs and the role of women. All of them generated considerable conflict and long-lasting divisiveness which was to shape the religious history of Ireland for successive generations. Gribben argues that it was only in the 1650s that conversion narratives emerged as a separate genre and that the most influential figure in this respect was John Rogers who in 1651 gathered a church in Christ Church Cathedral. He was to restrict church membership to gatherings of ‘visible saints’. Early Baptists in Ireland were viewed with great suspicion as they tried to shake off their early revolutionary reputations. However, after a slow start, by 1653 they had been planted in nine locations all of which had a high density of English soldiers. A leading figure in Dublin was Thomas Patient, a Particular Baptist, who called for separation from non-Baptists and eventually was appointed in Rogers's place to preach in Christ Church Cathedral. The number of clergy in Ireland, as in England also, fell in the 1640s and 1650s. A large number of Presbyterian ministers were recruited in Scotland and most were in favour of the Cromwellian settlement. By the end of the decade there was a total of seventy-four Presbyterian parishes in Ulster exercising vigorous social control. There was also the development of a Civil List of state-supported preachers and a system of Triers as in England. A belief in miracles and other extraordinary events was taken to new heights by the Quakers who saw themselves as channels of grace conversing with God and dismissing Scripture in favour of the ‘light within’. The response was severe with Henry Cromwell ordering their arrest throughout Ireland. Women constituted a substantial proportion of the membership of Rogers's church in Christ Church Cathedral and were allowed to give voice to their convictions in public yet this generally did not extend to preaching. Quaker women ignored the Pauline injunction to keep silent in churches and disrupted church services, burned books and acted as missionaries. Yet there were other radical women than the Quakers, the best example being Elizabeth Avery who published her letters in 1647. She came to be identified as a leading heretic believing that the Bible and sacraments had become redundant, claiming access to supernatural voices and rejecting the conventional doctrine of the resurrection of the dead. This is a book rich in detail and extending our knowledge of a complex decade in Irish history. The author has also provided a welcome bibliography and clear endnotes. The book deserves a wide readership among early modern historians and theologians.