The Catholic Church in Ireland (Irish: Eaglais Chaitliceach in Éireann) or Irish Catholic Church, is part of the worldwide Catholic Church in communion with the Holy See. With 3.7 million members, it is the largest Christian church in Ireland. In the Republic of Ireland's 2016 census, 78% of the population identified as Catholic; this was 6% lower than the 2011 figure and until 1980s and 1990s it was the national church of Ireland. By contrast, 41% of people in Northern Ireland identified as Catholic at the 2011 census; it is expected that this proportion will increase in the coming years.[1] The Archbishop of Armagh, as the Primate of All Ireland, has ceremonial precedence in the church. The church is administered on an all-Ireland basis. The Irish Catholic Bishops' Conference is a consultative body for ordinaries in Ireland.
Christianity has existed in Ireland since the 5th century and arrived from Roman Britain (most famously associated with Saint Patrick), forming what is today known as Gaelic Christianity. It gradually gained ground and replaced the old pagan traditions. The Catholic Church in Ireland cites its origin to this period and considers Palladius as the first bishop sent to the Gaels by Pope Celestine I. However, during the 12th century a stricter uniformity in the Western Church was enforced, with the diocesan structure introduced with the Synod of Ráth Breasail in 1111 and culminating with the Gregorian Reform which coincided with the Norman invasion of Ireland.
After the Tudor conquest of Ireland, the English Crown attempted to import the Protestant Reformation into Ireland. The Catholic Church was outlawed and adherents endured oppression and severe legal penalties for refusing to conform to the religion established by law — the Church of Ireland. By the 16th century, Irish national identity coalesced around Irish Catholicism. For several centuries, the Irish Catholic majority were suppressed. In the 19th century, the church and the British Empire came to a rapprochement. Funding for Maynooth College was agreed as was Catholic Emancipation to ward off revolutionary republicanism. Following the Easter Rising of 1916 and the creation of the Irish Free State, the church gained significant social and political influence. During the late 20th century, a number of sexual abuse scandals involving clerics emerged.
During classical antiquity, the Roman Empire conquered most of Western Europe but never reached Ireland. So when the Edict of Milan in 313 AD allowed tolerance for the Mediterranean-originated religion of Christianity and then the Edict of Thessalonica in 380 AD enforced it as the state religion of the Empire; covering much of Europe (including within the British Isles itself, Roman Britain); the indigenous Indo-European pagan traditions of the Gaels in Ireland remained normative. Aside from this independence, Gaelic Ireland was a highly decentralised tribal society, so mass conversion to a new system would prove a drawn out process even as the Christian religion began to gradually move into the island.[2]
There is no tradition of a New Testament figure visiting the island. Joseph of Arimathea was said to have come to Britain, Mary Magdalene, Martha and Lazarus of Bethany to France, but none were reputed to have seen Ireland itself. Instead, medieval Gaelic historians in works such as the Lebor Gabála Érenn attempted to link the historical narrative of their people (represented by the proto-Gaelic Scythians) to Moses in Egypt.[note 1] Furthermore, according to the Lebor Gabála Érenn, the lifetime of Jesus Christ was syncronised with the reigns of Eterscél, Nuadu Necht and Conaire Mór as High Kings of Ireland. In medieval tellings, Conchobar mac Nessa, a King of Ulster, was born at the same hour as Christ. Later in life, upon seeing an unexplained "darkening of the skies", Conchobar mac Nessa found out from a druí that Christ had been crucified. He fled into a rage, and died himself on the spot[3][4]