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.
Religion in Northern Ireland
The Presbyterian Church in Ireland, closely linked to the Church of Scotland in terms of theology and history, is the second-largest church and largest Protestant denomination. It is followed by the Anglican Church of Ireland, which was the state church of Ireland until it was disestablished by the "Irish Church Act 1869". In 2002, the much smaller Methodist Church in Ireland signed a covenant for greater co-operation and potential ultimate unity with the Church of Ireland. The Church of Ireland is part of the Anglican Communion.