The United Kingdom of Great Britain and Ireland (commonly known as the United Kingdom, Great Britain and Ireland, Great Britain and sometimes, as a synecdoche, as England)[1] was the formal name and the state form of the United Kingdom from 1 January 1801 until 12 April 1927. It was formed by the merger of the Kingdom of Great Britain (itself having been a merger of the Kingdoms of England and Scotland) and the Kingdom of Ireland, with Ireland being governed directly from Westminster through its Dublin Castle administration.
Following Irish independence on 6 December 1922, when the 1921 Anglo-Irish Treaty came into effect, the name continued in official use until it was changed to the United Kingdom of Great Britain and Northern Ireland by the Royal and Parliamentary Titles Act of 1927.
Under the terms of the Act of Union, the separate Parliament of Great Britain and the Parliament of Ireland were abolished and replaced by a united Parliament of the United Kingdom.[2] The new House of Commons consisted of all Members of Great Britain's 18th Parliament and 100 Irish MPs co-opted in a special election in 1801.[2] The new House of Lords consisted of all members of Great Britain's House of Lords, as well as four Lords Spiritual and twenty-eight Lords Temporal from the Irish House of Lords.[2] The new Parliament met in the Palace of Westminster, formerly the home of the Parliament of Great Britain and, until 1707, the Parliament of England.
Part of the trade-off for Irish Roman Catholics, who since 1652 were barred from voting or attending Parliament altogether under the Cromwellian Act of Settlement, was to be the granting of Catholic Emancipation, which had been fiercely resisted by the all-Anglican Irish Parliament. However, this was blocked by King George III who argued that emancipating Roman Catholics would breach his Coronation Oath to act as protector of Protestantism.
The merger was initially seen favourably in Ireland, given that the old Irish parliament was seen as hostile to the majority Catholic population, some of whose members had only been given the vote as late as 1794 and who were legally debarred from election to the body. The Roman Catholic hierarchy endorsed the Union. However, King George III's decision to block Catholic Emancipation fatally undermined the appeal of the Union. Leaders like Henry Grattan, who sat in the new parliament, having been leading members of the old one, were bitterly critical.
The eventual achievement of Catholic Emancipation in 1829, following a campaign by Daniel O'Connell, MP for County Clare, who had won election to Westminster and who could not for religious beliefs take the Oath of Supremacy, removed the main negative that had undermined the appeal of the old parliament, the exclusion of Catholics. From 1829 on a demand grew again for a native Irish parliament separate from Westminster. However, his campaign to repeal the Act of Union ultimately failed.
Aspects of the United Kingdom met with popularity in Ireland during the 122-year union. Hundreds of thousands flocked to Dublin for the visits of Queen Victoria in 1900, King Edward VII and Queen Alexandra in 1903 and 1907 and King George V and Queen Mary in 1911. About 210,000 Irishmen fought in Irish regiments of the United Kingdom and Allied armies in World War I, at a time when Ireland was the only home nation where conscription was not in force.
Figures such as Isaac Butt and Charles Stewart Parnell, the first leader of the Irish Parliamentary Party, campaigned for a version of all-Ireland self-government called home rule within the United Kingdom, which was nearly achieved in the 1880s under the (British) ministry of William Ewart Gladstone who introduced two Irish Home Rule Bills. However, the measures were defeated in Parliament, and following the ascension of the Conservatives to the majority, the issue was buried as long as that party was in power.
With the return to power of the Liberals in 1910 general election supported by the Irish Party under John Redmond who now held the balance of power in the Commons, the veto power of the Lords was removed under the Parliament Act 1911 and a Home Rule Bill introduced in 1912 passed Parliament as the Third Home Rule Act in 1914, but was temporarily suspended for the duration of World War I. However the constant delaying of Home Rule and the opposition of the Orange Order in Ulster created the frustration that eventually led to political violence and the 1916 Easter Rising. An attempt to introduce Irish self-government was made by PM Lloyd George in 1917 when he called an Irish Convention which after six months deliberating failed to agree on the inclusion or exclusion of Ulster. The European situation with the threat of conscription changed the political climate such that in the 1918 general election, the Irish Party lost most of its seats to the new Sinn Féin party.