Church of Ireland in the context of Anglican Communion

Christianity has been the largest religion in Ireland since the 5th century. After a pagan past of Antiquity, missionaries (most famously including Saint Patrick) 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.

George Berkeley (/ˈbɑːrkli/ BARK-lee; 12 March 1685 – 14 January 1753), known as Bishop Berkeley (Bishop of Cloyne of the Anglican Church of Ireland), was an Anglo-Irish philosopher, writer, and clergyman who is regarded as the founder of "immaterialism", a philosophical theory he developed which later came to be known as subjective idealism. He has also been called "the father of idealism" by German philosopher Arthur Schopenhauer. Berkeley played a leading role in the empiricism movement and was one of its pioneers. He was among the most cited philosophers of 18th-century Europe, and his works deeply influenced later thinkers such as Immanuel Kant and David Hume.

In 1709, Berkeley published his first major work An Essay Towards a New Theory of Vision, in which he discussed the limitations of human vision and advanced the theory that the proper objects of sight are not material objects, but light and colour. This foreshadowed his most well-known philosophical work A Treatise Concerning the Principles of Human Knowledge, published in 1710, which, after its poor reception, he rewrote in dialogue form and published under the title Three Dialogues Between Hylas and Philonous in 1713. In this book, Berkeley's views were represented by Philonous (Greek: "lover of mind"), while Hylas ("hyle", Greek: "matter") embodies Berkeley's opponents, in particular John Locke.

Unionism in Ireland is a political tradition that professes loyalty to the crown of the United Kingdom and to the union it represents with England, Scotland and Wales. The overwhelming sentiment of Ireland's Protestant minority, unionism mobilised in the decades following Catholic Emancipation in 1829 to oppose restoration of a separate Irish parliament. Since Partition in 1921, as Ulster unionism its goal has been to retain Northern Ireland as a devolved region within the United Kingdom and to resist the prospect of an all-Ireland republic. Within the framework of the 1998 Belfast Agreement, which concluded three decades of political violence, unionists have shared office with Irish nationalists in a reformed Northern Ireland Assembly. As of February 2024, they no longer do so as the larger faction: they serve in an executive with an Irish republican (Sinn Féin) First Minister.

Unionism became an overarching partisan affiliation in Ireland late in the nineteenth century. Typically Presbyterian agrarian-reform Liberals coalesced with traditionally Anglican, Orange Order allied, Conservatives against the Irish Home Rule Bills of 1886 and 1893. Joined by loyalist labour, on the eve of World War I this broad opposition to Irish self-government concentrated in Belfast and its hinterlands as Ulster unionism and prepared an armed resistance—the Ulster Volunteers.

Ulster Protestants are an ethnoreligious group in the Irish province of Ulster, where they make up about 43.5% of the population. Most Ulster Protestants are descendants of settlers who arrived from Great Britain in the early 17th century Ulster Plantation. This was the settlement of the Gaelic, Catholic province of Ulster by Scots and English speaking Protestants, mostly from the Scottish Lowlands and Northern England. Many more Scottish Protestant migrants arrived in Ulster in the late 17th century. Those who came from Scotland were mostly Presbyterians, while those from England were mostly Anglicans (see Church of Ireland). There is also a small Methodist community and the Methodist Church in Ireland dates to John Wesley's visit to Ulster in 1752. Although most Ulster Protestants descend from Lowland Scottish people (some of whose descendants consider themselves Ulster Scots), many descend from English, and to a lesser extent, from Irish, Welsh and Huguenots.

Since the 17th century, sectarian and political divisions between Ulster Protestants and Irish Catholics have played a major role in the history of Ulster, and of Ireland as a whole. It has led to bouts of violence and political upheaval, notably in the Irish Confederate Wars, the Cromwellian conquest of Ireland, the Williamite War, the Armagh disturbances, Irish Rebellion of 1798, the Irish revolutionary period, and the Troubles. Today, the vast majority of Ulster Protestants live in Northern Ireland, which was created in 1921 to have an Ulster Protestant majority, and in the east of County Donegal. Politically, most are unionists, who have an Ulster British identity and want Northern Ireland to remain part of the United Kingdom.

Anglo-Irish people (Irish: Angla-Éireannach) denotes an ethnic, social and religious grouping consisting mostly of the descendants and successors of the English Protestant Ascendancy in Ireland. Predominantly, the Anglo-Irish belong to the Anglican Church of Ireland, which was the established Church of Ireland until 1871 or, to a lesser extent, to one of the English Dissenting Churches, such as Baptists, Presbyterians, the Methodist Church. However, some were Roman Catholics. They often defined themselves simply as "British", or less frequently as "Anglo-Irish", "Irish" or "English". Many became notable as administrators in the British Empire or as senior army and naval officers. The Kingdom of England and Great Britain were in a real union with the Kingdom of Ireland for over a century, before politically uniting into the United Kingdom of Great Britain and Ireland in 1801.

The term is not usually applied to Presbyterians in the province of Ulster, whose ancestry is mostly Lowland Scottish, rather than English or Irish, and who are sometimes identified as Ulster Scots. The Anglo-Irish hold a wide range of political views, with some being outspoken Irish nationalists, but most overall being Unionists. And while most of the Anglo-Irish originated in the English diaspora in Ireland, others were descended from families of the old Gaelic nobility of Ireland.

The Kingdom of Ireland (Early Modern Irish: Ríoghacht Éireann; Modern Irish: Ríocht na hÉireann, pronounced [ənˠ ˌɾˠiːxt̪ˠ ˈeːɾʲən̪ˠ]) was a dependency of England from 1542 to 1707, and subsequently Great Britain from 1707 to 1800. It was ruled by the monarchs of England and then of Great Britain in personal union, and was administered from Dublin Castle by a viceroy appointed by the English king: the Lord Lieutenant of Ireland. By the late 17th century, the state was dominated by the Protestant Anglo-Irish minority, known as the Protestant Ascendancy. The Protestant Church of Ireland was the state church. The Parliament of Ireland was almost exclusively Anglo-Irish. From 1661, the administration controlled an Irish army. Although formally a kingdom in personal union on equal footing with England and later Great Britain, for most of its history it was de facto a dependency with a viceroy sent as an envoy from London. This status was enshrined in the Declaratory Act 1719, also known as the Irish Parliament Act 1719.

The territory of the kingdom comprised that of the former Lordship of Ireland, founded in 1177 by King Henry II of England and the English Pope Adrian IV, after the Anglo-Norman invasion of Ireland. By the 16th century, the Pale, the area of effective English rule, had shrunk greatly; most of Ireland was held by Gaelic nobles as minor principalities notionally subject to London but independent in practice. By the terms of the Crown of Ireland Act 1542, Henry VIII of England became "King of Ireland", theoretically elevating Ireland to coequal status with England as a kingdom in personal union. There followed an expansion of English control during the Tudor conquest. This sparked the Desmond Rebellions and the Nine Years' War. The conquest of the island was completed early in the 17th century. It involved the confiscation of land from the native Irish Catholics and its colonisation by Protestant settlers from Britain. Most Catholic countries at the time did not recognise Protestant monarchs as legitimate kings of Ireland (or indeed of England), instead supporting the Jacobite government-in-exile from 1688 onwards.

Saint Patrick (Latin: Pātricius; Irish: Pádraig Irish pronunciation: [ˈpˠɑːɾˠɪɟ] or Irish pronunciation: [ˈpˠaːd̪ˠɾˠəɟ]; Welsh: Padrig) was a fifth-century Romano-British Christian missionary and bishop in Ireland. Known as the "Apostle of Ireland", he is the primary patron saint of Ireland, the other patron saints being Brigid of Kildare and Columba. He is also the patron saint of Nigeria. Patrick was never formally canonised by the Catholic Church, having lived before the current laws were established for such matters. He is venerated as a saint in the Catholic Church, the Lutheran Church, the Church of Ireland (part of the Anglican Communion), and in the Eastern Orthodox Church, where he is regarded as equal-to-the-apostles and Enlightener of Ireland.

The dates of Patrick's life cannot be fixed with certainty, but there is general agreement that he was active as a missionary in Ireland during the fifth century. A recent biography on Patrick shows a late fourth-century date for the saint is possible. According to tradition dating from the early Middle Ages, Patrick was the first bishop of Armagh and Primate of Ireland, and is credited with bringing Christianity to Ireland (despite evidence of some earlier Christian presence on the island), and converting Ireland from paganism in the process.

The Parliament of Ireland (Irish: Parlaimint na hÉireann) was the legislature of the Lordship of Ireland, and later the Kingdom of Ireland, from 1297 until the end of 1800. It was modelled on the Parliament of England and from 1537 comprised two chambers: the House of Commons and the House of Lords. The Lords were members of the Irish peerage ('lords temporal') and bishops ('lords spiritual'; after the Reformation, Church of Ireland bishops). The Commons was directly elected, albeit on a very restricted franchise. Parliaments met at various places in Leinster and Munster, but latterly always in Dublin: in Christ Church Cathedral (15th century), Dublin Castle (to 1649), Chichester House (1661–1727), the Blue Coat School (1729–31), and finally a purpose-built Parliament House on College Green.

The main purpose of parliament was to approve taxes that were then levied by and for the Dublin Castle administration. Those who would pay the bulk of taxation, namely the clergy, merchants, and landowners, also comprised the members. Only the "English of Ireland" were represented until the first Gaelic lords were summoned during the 16th-century Tudor reconquest. Under Poynings' Law of 1495, all Acts of Parliament had to be pre-approved by the Irish Privy Council and English Privy Council. Parliament supported the Irish Reformation and Catholics were excluded from membership and voting in penal times. The Constitution of 1782 amended Poynings' Law to allow the Irish Parliament to initiate legislation. Catholics were re-enfranchised under the Roman Catholic Relief Act 1793.

Clive Staples Lewis (29 November 1898 – 22 November 1963) was a British author, literary scholar and Anglican lay theologian. He held academic positions in English literature at both Magdalen College, Oxford (1925–1954), and Magdalene College, Cambridge (1954–1963). He is best known as the author of The Chronicles of Narnia, but he is also noted for his other works of fiction, such as The Screwtape Letters and The Space Trilogy, and for his non-fiction Christian apologetics, including Mere Christianity, Miracles and The Problem of Pain.

Lewis was a close friend of J. R. R. Tolkien, the author of The Lord of the Rings. Both men served on the English faculty at the University of Oxford and were active in the informal Oxford literary group known as the Inklings. According to Lewis's 1955 memoir Surprised by Joy, he was baptized in the Church of Ireland but fell away from his faith during adolescence. Lewis returned to Anglicanism at the age of 32, owing to the influence of Tolkien and other friends, and he became an "ordinary layman of the Church of England". Lewis's faith profoundly affected his work, and his wartime radio broadcasts on the subject of Christianity brought him wide acclaim.

The Bishop of Cloyne is an episcopal title that takes its name after the small town of Cloyne in County Cork, Ireland. In the Roman Catholic Church, it is a separate title; but, in the Church of Ireland, it has been united with other bishoprics.

Charles Stewart Parnell (27 June 1846 – 6 October 1891) was an Irish nationalist politician who served as a Member of Parliament (MP) in the United Kingdom from 1875 to 1891, Leader of the Home Rule League from 1880 to 1882, and then of the Irish Parliamentary Party from 1882 to 1891, who held the balance of power in the House of Commons during the Home Rule debates of 1885–1886. He fell from power following revelations of a long-term affair, and died at age 45.

Born into a powerful Anglo-Irish Protestant landowning family in County Wicklow, he was a land reform agitator and founder of the Irish National Land League in 1879. He became leader of the Home Rule League, operating independently of the Liberal Party, winning great influence by his balancing of constitutional, radical, and economic issues, and by his skilful use of parliamentary procedure.

The Nonjuring schism refers to a split in the established churches of England, Scotland and Ireland, following the deposition and exile of James II and VII in the 1688 Glorious Revolution. As a condition of office, clergy were required to swear allegiance to the ruling monarch; for various reasons, some refused to take the oath to his successors, William III and II and Mary II. These individuals were referred to as Non-juring, from the Latin verb iūrō, or jūrō, meaning "to swear an oath".

In the Church of England, an estimated 2% of priests refused to swear allegiance in 1689, including nine bishops. Ordinary clergy were allowed to keep their positions but after efforts to compromise failed, the six surviving bishops were removed in 1691. The schismatic Non-Juror Church was formed in 1693 when Bishop William Lloyd appointed his own bishops. His action was opposed by the majority of English Non-Jurors, who remained within the Church of England and are sometimes referred to as "crypto-Non-Jurors". Never large in numbers, the Non-Juror Church rapidly declined after 1715, although minor congregations remained in existence until the 1770s.

Protestantism is a Christian community on the island of Ireland. In the 2011 census of Northern Ireland, 48% (883,768) described themselves as Protestant, which was a decline of approximately 5% from the 2001 census. In the 2011 census of the Republic of Ireland, 4.27% of the population described themselves as Protestant. In the Republic, Protestantism was the second largest religious grouping until the 2002 census in which they were exceeded by those who chose "No Religion". Some forms of Protestantism existed in Ireland in the early 16th century before the English Reformation, but demographically speaking, these were very insignificant and the real influx of Protestantism began only with the spread of the English Reformation to Ireland. The Church of Ireland was established by King Henry VIII of England, who had himself proclaimed as King of Ireland.

The Protestant Ascendancy (Irish: An Chinsealacht Phrotastúnach; also known as the Ascendancy) was the sociopolitical and economical domination of Ireland between the 17th and early 20th centuries by a small Anglican ruling class, whose members consisted of landowners, barristers, politicians, clergymen, military officers and other prominent professions. They were either members of the Church of Ireland or the Church of England and wielded a disproportionate amount of social, cultural and political influence in Ireland. The Ascendancy existed as a result of British rule in Ireland, as land confiscated from the Irish Catholic aristocracy was awarded by the Crown to Protestant settlers from Great Britain.

During the Tudor conquest of Ireland, land owned by Irish nobles was gradually confiscated by the Crown over several decades. These lands were sold to colonists from Great Britain as part of the plantations of Ireland, with the province of Ulster being a focus in particular for colonisation by Protestant settlers after the Battle of Kinsale. These settlers went on to form the new aristocracy and gentry of Ireland, as the Gaelic nobility had either died, fled with the Flight of the Earls or allied with the Crown. They eventually came to be known as the Anglo-Irish people. From the 1790s the phrase became used by the main two identities in Ireland: nationalists, who were mostly Catholics, used the phrase as a "focus of resentment", while for unionists, who were mostly Protestants, it gave a "compensating image of lost greatness".

Civil parishes (Irish: paróistí sibhialta, paróistí dlí) are units of territory in the island of Ireland that have their origins in old Gaelic territorial divisions. They were adopted by the Anglo-Norman Lordship of Ireland and then by the Elizabethan Kingdom of Ireland, and were formalised as land divisions at the time of the Plantations of Ireland. They may correspond, in both name and boundary, with Church of Ireland and Roman Catholic parishes. Their use as administrative units was gradually replaced by Poor Law Divisions in the 19th century, although they were not formally abolished. Today they are still sometimes used for legal purposes, such as to locate property in deeds of property registered between 1833 and 1946.

The title of Supreme Head of the Church of England was created in 1531 for King Henry VIII when he first began to separate the Church of England from the authority of the Holy See and allegiance to the papacy, then represented by Pope Clement VII. The Act of Supremacy of 1534 confirmed the King's status as having supremacy over the church and required the nobility to swear an oath recognising Henry's supremacy. By 1536, Henry had broken with Rome, seized assets of the Catholic Church in England and Wales and declared the Church of England as the established church with himself as its head. Pope Paul III excommunicated Henry in 1538 over his divorce from Catherine of Aragon.

Similarly, in Ireland, the Parliament of Ireland passed the Act of Supremacy (Ireland) 1537, establishing Henry as Supreme Head of the Church of Ireland. Again Henry seized assets of the Catholic Church in Ireland and declared the Church of Ireland as the established church with himself as its head. He made himself King of Ireland in 1541, which reinforced his status (previous English kings had held the title of Lord of Ireland, and the island was considered a papal fief based on an 1155 papal bull).