Christianity in Ireland

has been the largest religion in Ireland since the 5th century. After a pagan past of Antiquity, missionaries converted the Irish tribes to Christianity in quick order. This produced a great number of saints in the Early Middle Ages, as well as a faith interwoven with Irish identity for centuries since − though less so in recent times.
Most Christian churches are organized on an "all-Ireland" basis, including both the Republic of Ireland and Northern Ireland. In the 2022 census, 76.1% of residents in the Republic of Ireland identified as Christians: 69.1% as Catholics, 4.2% as Protestants, 2.1% as Orthodox Christians and 0.7% as other Christians. In the 2021 Northern Irish census, 79.7% of residents identified as Christians: 42.3% as Catholics, 16.6% as Prebysterian, 11.5% as Church of Ireland members, 2.4% as Methodist and 6.9% as other Christians. Orthodoxy has been the fastest growing branch of Christianity in Ireland since 1991.
Ireland has for many centuries been noted for its perpetually strong Christian faith. However, in recent decades, a "Quiet Revolution" had taken place which lead to increased secularity in various aspects of Irish society. The 1972 amendment of the Irish constitution, for example, removed the "special position" of the Catholic Church as "guardian of the Faith" and the recognition of other named religious denominations in Ireland. However, in 1983 abortion was banned by the Eighth Amendment of the Irish constitution which recognized the right to life of the unborn as equal to the right to life of the mother and was advocated for by representatives of the Catholic Church. Only in 2018 was a referendum held to repeal the Eighth Amendment, and this repeal marks a significant point in the secularization of the constitution made possible by a significant secularization of the people. Today, a large proportion of Irish Christians are thought to be nominally so, for reasons ranging from cultural to apathetic. Catholicism has been declining in the Republic of Ireland.

History

The introduction of Christianity to Ireland dates to sometime before the 5th century, presumably through interactions with Roman Britain. A single documented event dates from 430, when Palladius, a bishop born in France, was sent by Pope Celestine I to minister to the "Scots believing in Christ". While this is evidence of Christianity existing in Ireland prior to 430, nothing more may be said for certain.
The early Irish church developed a strong monastic tradition. Some Eastern Orthodox Christians argue that the Irish church also had an Apostolic connection and was effectively a provincial form of Eastern Orthodox Christianity up until the East-West Schism of 1054.

Apostle of the Irish

The traditional story of Saint Patrick says he was from Bannavem Taburniae, the location of which is unclear. His birthplace is not known with any certainty; some traditions place it in England—one identifying it as Glannoventa —but claims have also been advanced for locations in present-day Scotland
or in Wales He was captured and brought to Ireland and later sold as a slave. After escaping and returning to his own people, he began to receive visions of the cry of the Pagan Irish pleading him to come among them. Believing that he had been called by God to mission to the Irish, he entered the monastery of St Martin of Tours in Gaul. After his consecration as a bishop in Rome, he was sent by Pope Celestine to Ireland, where he arrived in 432 as a missionary. He was not sent by Rome but came in defiance of ecclesiastical law which forbade bishops leaving their diocese. Patrick's 'Declaration' or 'Confession' was an answer to the charges brought against him in England. Patrick died in 461. The Uí Néill dynasty of Armagh got Tireachan and Muirchu to write spurious accounts of Patrick to establish Armagh's claims to the revenues of the churches and monasteries of Ireland. Brehon Law at the time granted revenues forever to the heirs of the founder. When southerner Brian Ború assumed the High Kingship of Ireland around 1000 AD, he had his secretary write into the Book of Armagh a confirmation of the right of Armagh to all church revenues in Ireland. It is said that Patrick built 365 churches and consecrated an equal number of bishops, established schools and convents, and held synods.

Missionaries abroad

In the 6th and 7th centuries missionaries from Ireland to England and Continental Europe spread news of the flowering of learning, and scholars from other nations moved to Irish monasteries. The excellence and isolation of these monasteries helped preserve Latin learning during the Early Middle Ages. The period of Insular art - mainly in the fields of illuminated manuscripts, metalworking, and sculpture - flourished and produced such treasures as the Book of Kells, the Ardagh Chalice, and the many carved stone crosses that dot the island of Ireland.
Image:KellsFol292rIncipJohn.jpg|thumb|200px|A page from the Book of Kells that opens the Gospel of John
These monasteries served as sanctuaries to many of the continent's great scholars and theologians. It was here that the lamp of Latin learning was preserved for the ages. During this age, the great illuminated manuscripts of Ireland were produced. Arguably the finest example of such works is The Book of Kells, now displayed at Trinity College, Dublin.
The first significant renewal of learning in the West came with the Carolingian Renaissance of the Early Middle Ages. Charlemagne, advised by Peter of Pisa and by Alcuin of York, attracted the scholars of England and Ireland, and by decree in AD 787 established schools in every abbey in his empire. These schools, from which the term scholasticism derives, became centres of medieval learning. During the early Scholastic period, knowledge of the Greek language had vanished in the west except in Ireland, where it was widely dispersed in the monastic schools.
Irish scholars had a considerable presence in the Frankish court, where they were renowned for their learning. Among them was Johannes Scotus Eriugena, one of the founders of scholasticism. Eriugena was the most significant Irish intellectual of the early monastic period, and an outstanding philosopher in terms of originality. He had considerable familiarity with the Greek language, and translated many works into Latin, affording access to the Cappadocian Fathers and the Greek theological tradition.

The Vikings arrive

During the ninth and tenth centuries, waves of Norse warriors ransacked Ireland. The monasteries were favourite Viking targets because of their treasures of silver religious ornaments.

Cambro-Normans

In the first year of his reign, Henry II of England procured a Papal bull from the English-born Pope Adrian IV authorising him to proceed to Ireland "to check the torrent of wickedness to reform evil manners, to sow the seeds of virtue". The following year, Adrian authorised Henry II to invade Ireland in order "to proclaim the truths of the Christian religion to a rude and ignorant people"; on condition that a penny should be paid annually from each house to the See of Rome.
In 1168 Macmurrogh, King of Leinster, driven from his kingdom,sought Henry's aid, and then Adrian's Bull was remembered. A contingent of Cambro-Norman knights went to Ireland in 1169. In 1171 Henry himself landed at Waterford. The king proceeded to Dublin where he spent the winter and received the submission of many Irish kings.
In late 1171, an assembly of the Irish clergy gathered at Cashel and proclaimed Henry's title to the sovereign dominion of Ireland. The assembly took the oath of fidelity to him and his successors.
Pope Alexander III, gratified with this extension of his dominion, issued in September 1172 a brief confirming the bull of Adrian and expressing a hope that "the barbarous nation" would attain under the government of Henry "to some decency of manners"; he also wrote three epistles—one to Henry II, one to the kings and nobles of Ireland, and one to its ecclesiastical hierarchy—enjoining obedience of Ireland to England, and of both to the see of Saint Peter.
In some ways, the change was advantageous to the church hierarchy. Under the ancient system, the native chieftains were absolute masters over all their followers, including the clergy. According to the new order introduced by Henry II, the chieftains no longer had authority over the clergy. To maintain their sovereignty over the Irish clergy, the English kings filled the vacant sees mostly with Englishmen. The Irish clergy in turn appealed to Rome to confirm their nomination. Jealousy, hostility and disputes characterised the relations between the English and the Irish ecclesiastics; the latter sought to transfer their allegiance as churchmen from the sovereign of England to the pope of Rome, and so the struggle for supremacy lasted for centuries.
The Crown of England did not gain full control of Ireland until the 16th and 17th centuries; the whole island was subjected to a number of military campaigns in the period from 1534 to 1691. During this period, the island was colonised by English and Scottish Protestant settlers. Most of the native Irish remained Catholic.

Reformation

In 1536 during the English Reformation, King Henry VIII of England arranged to be declared head of the Church in Ireland through the Act of Supreme Head of the Church in Ireland passed by the Irish Reformation Parliament.

Union with Great Britain

When Ireland was incorporated in 1801 into the new United Kingdom of Great Britain and Ireland, the Church of Ireland was also united with the Church of England to form the United Church of England and Ireland. At the same time, one archbishop and three bishops from Ireland were given seats in the House of Lords at Westminster, joining the two archbishops and twenty-four bishops from the Church of England.
In 1833, the British Government proposed the Irish Church Measure to reduce the 22 archbishops and bishops who oversaw the Anglican minority in Ireland to a total of 12 by amalgamating sees and using the revenues saved for the use of parishes. This sparked the Oxford Movement, which was to have wide repercussions for the Anglican Communion.
As the official established church, the Church of Ireland was funded partially by tithes imposed on all Irish citizens, irrespective of the fact that it counted only a minority of the populace among its adherents; these tithes were a source of much resentment which occasionally boiled over, as in the "Tithe War" of 1831/36. Eventually, the tithes were ended, replaced with a lower levy called the tithe rentcharge.
The Irish Church Act 1869 finally ended the role of the Church of Ireland as the state church. This terminated both state support and parliament's role in its governance, but also took into government ownership much church property. Compensation was provided to clergy, but many parishes faced great difficulty in local financing after the loss of rent-generating lands and buildings. The Church of Ireland made provision in 1870 for its own government, led by a General Synod, and with financial management by a Representative Church Body. With disestablishment in 1869, the last remnants of tithes were abolished and the Church's representation in the House of Lords also ceased.