Despite the best efforts of Elizabethan government, Ireland remained resolutely Catholic. The monograph offers a new take on the notorious ‘failure’ of the Irish Reformation. It argues that perceptions of an almost complete absence of God’s grace in Irish civil society promoted a growing emphasis on the necessity of absolute obedience to an increasingly abstracted state authority. This process was, paradoxically, secularizing, even as it drew on fervent religious convictions. Here absolutist theories of government, and proto-modern conceptions of an impersonal state, were developed by figures in and around the ruling regime in the Irish kingdom. Such concepts would only later come into their own elsewhere. In doing so, the study places Ireland within the wider context of English political and religious reform and European intellectual history. It argues that Irish godly Calvinism played a very different role in the history of political thought than the one usually assigned to it, because in Ireland absolutist as opposed to constitutionalist theories of government came to dominate.