Gaels and early Christianity
The Christianisation of Ireland is associated with the 5th century activities of St. Patrick
The Roman Empire never reached Ireland; so when the Edict of Milan in 313 AD allowed tolerance for the Levantine-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 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.
The earliest stages of Christianity in Ireland during its 5th century arrival are somewhat obscure, however, native Christian figures including Ailbe, Abbán, Ciarán and Declán, later venerated as saint by the Christians, are known. These were typically in Leinster and Munster. The early stories of these people mention journeys to Roman Britain, Roman Gaul and even Rome itself. Indeed, Pope Celestine I is held to have sent Palladius to evangelise the Gaels in 431, but this did not gather much steam. However, the figure most associated with the Christianisation of Ireland is Patrick (Maewyn Succat), a Romano-British nobleman, who was captured by the Gaels during a raid, as Roman rule in Britain was retracting. Patrick contested with the druí, targeted the local royalty for conversion and re-orientated Irish Christianity to having Armagh as the preeminent seat of power; an ancient royal site associated with the goddess Macha (an aspect of An Morríghan).
Gregorian Reform and Norman influence
A reform to the Roman style diocesan system developed slowly after the Synod of Rathbreasail in 1111. In 1155, Pope Adrian IV, the English born Pope, issued a papal bull known as Laudabiliter. This purported to give Henry, Duke of Normandy (also known as King Henry II of England ) permission to invade Ireland as a means of strengthening the Papacy's control over the Irish Church. The Norman invasion of Ireland began in 1169, under the authority of this bull. Adrian IV's successor, Pope Alexander III, ratified the Laudabiliter and claimed to give Henry dominion over the "barbarous nation" of Ireland so that its "filthy practises" may be abolished, its Church brought into line, and that the Irish pay their tax to Rome. After the Norman invasion, a greater number of foreign-born prelates were appointed.
Counter-Reformation and suppression
A confusing but defining period arose during the English Reformation in the 16th century, with monarchs alternately for or against papal supremacy. When on the death of Queen Mary in 1558, the church in England and Ireland broke away completely from the papacy, all but two of the bishops of the church in Ireland followed the decision. Very few of the local clergy led their congregations to follow. The new body became the established state church, which was grandfathered in the possession of most church property. This allowed the Church of Ireland to retain a great repository of religious architecture and other religious items, some of which were later destroyed in subsequent wars. A substantial majority of the population remained Catholic, despite the political and economic advantages of membership in the state church. Despite its numerical minority, however, the Church of Ireland remained the official state church for almost 300 years until it was disestablished on 1 January 1871 by the Irish Church Act 1869 that was passed by Gladstone's Liberal government.
The effect of the Act of Supremacy 1558 and the papal bull of 1570 (Regnans in Excelsis) legislated that the majority population of both kingdoms to be governed by an Anglican ascendancy. After the defeat of King James II of The Three Kingdoms in 1690, the Test Acts were introduced which began a long era of discrimination against the recusant Catholics of the kingdoms.
Between emancipation and the revolution
The slow process of reform from 1778 on led to Catholic Emancipation in 1829. By then Ireland was a part of the newly created United Kingdom of Great Britain and Ireland.
Following the partition of Ireland
Mass in a Connemara Cabin
by Aloysius O'Kelly
, 1883. The custom of priests saying Mass secretly in people's homes dates to the penal laws
-era. It was especially common in rural areas.
From the time that Ireland achieved independence, the church came to play an increasingly significant social and political role in the Irish Free State and following that, the Republic of Ireland. For many decades, Catholic influence (coupled with the rural nature of Irish society) meant that Ireland was able to uphold family-orientated social policies for longer than most of the West, contrary to the laissez-faire-associated social liberalism of the British and Americans. This cultural direction was particularly prominent under Éamon de Valera. For example, from 1937 until 1995, divorce and remarriage was not permitted (in line with Catholic views of marriage).[note 1] Similarly, the importation of contraception[note 2] abortion and pornography were also resisted; media-depictions perceived to be detrimental to public morality were also opposed by Catholics. In addition the church largely controlled many of the state's hospitals, and most schools, and remained the largest provider of many other social services.
At the partition of Ireland in 1922, 92.6% of the south's population were Catholic while 7.4% were Protestant. By the 1960s, the Anglican and Protestant population had fallen by half, mostly due to emigration in the early years of Irish independence, with some Anglicans preferring to live within the UK. However, in the early 21st century the percentage of Protestants in the Republic has risen slightly, to 4.2%, and the absolute numbers to over 200,000, almost equal to the number in 1920, due to immigration and a modest flow of conversions from Catholicism. The Catholic Church's policy of Ne Temere, whereby the children of marriages between Catholics and Protestants had to be brought up as Catholics,[note 3] also helped to uphold Catholic hegemony.
In both parts of Ireland, church policy and practice changed markedly after the Vatican II reforms of 1962. Probably the largest change was that Mass could be said in vernacular languages instead of Latin, and in 1981 the church commissioned its first edition of the Bible in the Irish language, but the Church overwhelmingly uses English. Archbishop John Charles McQuaid was uneasy about the introduction of an English liturgy and ecumenical revisions, finding it offensive to Catholic sensibilities; he wished to uphold the liturgy in Latin, while also offering Irish as the vernacular (he promoted an Irish language provision more than other Bishops).
Since the Celtic Tiger and the furtherance of cosmopolitanism in Ireland, Catholicism has been one of the traditional elements of Ireland to fall into decline; particularly in urban areas. Fewer than one in five Catholics attend Mass on any given Sunday in Dublin with many young people only retaining a marginal interest in religion the Archbishop of Dublin, Diarmuid Martin, said in May 2011. According to an Ipsos MRBI poll by the Irish Times, the majority of Irish Catholics do not attend mass weekly, with almost 62% rejecting key parts of Catholicism such as transubstantiation. After the results of both the 2015 same-sex marriage and 2018 abortion referendums, Una Mullally, a liberal journalist who writes for The Guardian claimed that "the fiction of Ireland as a conservative, dogmatically Catholic country has been shattered".