Religion in the Republic of Ireland
The predominant religion in the Republic of Ireland is Christianity, with the largest church being the Roman Catholic Church. The Irish constitution says that the state may not endorse any particular religion and guarantees freedom of religion.
Church of Ireland
The Church of Ireland claimed that in breaking with Rome the reformed established church was reverting to a condition that had obtained in the church in Ireland prior to the 12th century – the independent character of Celtic Christianity. Modern scholarship, however, sees the early Irish church as different to but still a part of Roman Christianity, with the result that the Church of Ireland and the Irish Roman Catholic church can both claim descent from St Patrick.