Beginning with Catholic attitudes to the Act of Union, this work traces various elements in the interrelationship between the Catholic Church and the state in Ireland in the 19th century. Catholicism’s role in the Protestant state for most of the century was tempered and conditioned by its relationship with the various Protestant churches in the country. In the development of its infrastructure, facilitating as it did along with other factors the ‘devotional revolution’, the church was in many ways dependent upon Protestant financial help. The ironies and complexities of this situation is a consistent theme in these essays. Although the religion of the vast majority of the Irish people Catholicism, in its institutional aspect, felt itself to be undervalued and underappreciated by the Protestant state.Its dealings with the state where tempered by its relative poverty and it dependence on the state for various benefactions not least the generous provision for Catholic clerical education. For the first time in the historiography, some attention is paid to the relations between the Catholic Churches in Ireland and England in an era when the future cardinal Nicholas Wiseman attempted to pose as an unofficial adviser to government on Irish and Vatican affairs, in circumstances which caused resentment among Irish Catholic churchmen.