The interpretation of sixteenth-century Irish history is fraught with difficulty, constructed as it is on an inadequate evidential basis and on centuries of ideological turmoil. In the matter of religion, Irish historians of the mid-twentieth century placed great emphasis upon the inevitability of the failure of Protestantism. From the 1970s this sense of manifest destiny fell out of favour, and instead a generation of writers began to pose more searching questions about precisely when and why the Irish Reformation failed. Henry Jefferies's own early work on the 1560 Irish parliament was influenced by reaction against the inevitability thesis, and he has for some years been contributing critical and thoughtful articles to the debate generated by Nicholas Canny, Ciarán Brady and others. But in this well-researched volume, covering religious belief and behaviour for the whole century, he provides a vigorous challenge to some of the historians with whom he had previously identified. He is determined to put the religious conviction back into the Reformation debate, and to question arguments built upon a secularist view of competing interests and political manipulation. There are two stories being told here. The one about the choices made by the Tudor crown and its agents remains largely familiar: Jefferies documents the failures of consistent royal or conciliar policy-making, the deficiencies of most of the supposed leaders of the Reformation on the ground, the fiscal and organisational weaknesses of the Irish Church. His most distinctive point here is that historians have placed undue emphasis on the failure to establish an Irish university before the foundation of Trinity College in 1592. Other, cheaper, and more effective modes of training – scholarships to English universities, some sort of seminary for parish clergy – could surely have been tried and might have achieved more commitment to Protestantism. The second story is a greater challenge to existing scholarship: the Catholic faith of the Old English community was never really weakened even in the years when Sir Henry Sidney, as Lord Deputy, managed to enforce a high level of superficial conformity on Dublin. Jefferies follows Colm Lennon in arguing that the ‘lords of Dublin’ never allowed self-interest to shake their deep commitment to the Catholic faith. We should, he suggests, take the lucubrations of English observers, with their laments about papistry, seriously. None believed that there was any internalisation of the new faith. The evidence for general support of Catholic institutions and rituals is indeed strong, and the book constructs an impressive argument upon this. The only danger is that at times it protests too much: there were other motives for both Irish communities to oppose English authority, and to emphasise political alienation is not necessarily to denigrate the power of religious commitment.