Irish War of Independence in the context of "Irish Free State"

The 1921 Anglo-Irish Treaty (Irish: An Conradh Angla-Éireannach), commonly known in Ireland as The Treaty and officially the Articles of Agreement for a Treaty Between Great Britain and Ireland, was an agreement between the government of the United Kingdom of Great Britain and Ireland and the government of the Irish Republic that concluded the Irish War of Independence. It provided for the establishment of the Irish Free State within a year as a self-governing dominion within the "community of nations known as the British Empire", a status "the same as that of the Dominion of Canada". It also provided Northern Ireland, which had been created by the Government of Ireland Act 1920, an option to opt out of the Irish Free State (Article 12), which was exercised by the Parliament of Northern Ireland.

The agreement was signed in London on 6 December 1921, by representatives of the British government (which included Prime Minister David Lloyd George, who was head of the British delegates, and Winston Churchill, who was Secretary of State for the Colonies) and by representatives of the government of the Irish Republic (which included Michael Collins, who was Secretary of State for Finance, and Arthur Griffith, who was Secretary of State for Foreign Affairs). The Irish representatives had plenipotentiary status (negotiators empowered to sign a treaty without reference back to their superiors) acting on behalf of the Irish Republic, though the British government declined to recognise that status. As required by its terms, the agreement was approved by "a meeting" of the members elected to sit in the House of Commons of Southern Ireland and [separately] by the British Parliament. In reality, Dáil Éireann (the legislative assembly for the de facto Irish Republic) first debated then approved the treaty; members then went ahead with the "meeting". Though the treaty was narrowly approved, the split led to the Irish Civil War, which was won by the pro-treaty side.

The Government of Ireland Act 1920 (10 & 11 Geo. 5. c. 67) was an act of the Parliament of the United Kingdom. The Act's long title was "An Act to provide for the better government of Ireland"; it is also known as the Fourth Home Rule Bill or (inaccurately) as the Fourth Home Rule Act and informally known as the Partition Act. The Act was intended to partition Ireland into two self-governing polities: the six north-eastern counties were to form "Northern Ireland", while the larger part of the country was to form "Southern Ireland". Both territories were to remain part of the United Kingdom of Great Britain and Ireland and provision was made for their future reunification through a Council of Ireland. The Act was passed by the British Parliament in November 1920, received royal assent in December and came into force on 3 May 1921.

The smaller Northern Ireland was duly created with a devolved government and remained in the UK. The larger Southern Ireland was not recognised by most of its citizens, who instead recognised the self-declared Irish Republic in the ongoing Irish War of Independence. The conflict resulted in the Anglo-Irish Treaty in December 1921. Under the treaty, Ireland would leave the UK (with the option for Northern Ireland to opt out and remain in the UK, which it immediately did) in December 1922 and become the Irish Free State, which would later evolve into today's Republic of Ireland. The institutions set up under this Act for Northern Ireland continued to function until they were suspended by the British parliament in 1972 as a consequence of the Troubles.

Southern Ireland (Irish: Deisceart Éireann, pronounced [dʲɛʃcəɾˠt̪ˠ ˈeːɾʲən̪ˠ]) was the larger of the two parts of Ireland that were created when Ireland was partitioned by the Government of Ireland Act 1920. It comprised 26 of the 32 counties of Ireland or about five-sixths of the area of the island, whilst the remaining six counties, which occupied most of Ulster in the north of the island, formed Northern Ireland.

The Act of 1920, which became effective on 3 May 1921, was intended to create two self-governing territories within Ireland, each with its own parliament and governmental institutions, and both remaining within the United Kingdom of Great Britain and Ireland. It also contained provisions for co-operation between the two territories and for the eventual reunification of Ireland. However, in the 1921 elections for Southern Ireland's House of Commons, Sinn Féin candidates won 124 of the 128 seats (all candidates were unopposed and no actual polling occurred), and ignored the parliament, assembling instead as the Second Dáil. The House of Commons of Southern Ireland—consisting of the four unionist members—met only once, while the Senate only met twice. Continuing unrest resulted in the Anglo-Irish Treaty and the Provisional Government, which administered Southern Ireland from 16 January 1922 to 5 December 1922: effectively a transitional administration for the period between the ratifying of the Anglo-Irish Treaty and the establishment of the Irish Free State. Its legitimacy was disputed by the Anti-Treaty delegates to Dáil Éireann.

In the history of the 20th century, the interwar period, also known as the interbellum (from Latin inter bellum 'between the war[s]'), lasted from 11 November 1918 to 1 September 1939 (20 years, 9 months, 21 days) – from the end of World War I (WWI) to the beginning of World War II (WWII). It was relatively short, yet featured many social, political, military, and economic changes throughout the world. Petroleum-based energy production and associated mechanisation led to the prosperous Roaring Twenties, a time of social and economic mobility for the middle class. Automobiles, electric lighting, radio, and more became common among populations in the first world. The era's indulgences were followed by the Great Depression, an unprecedented worldwide economic downturn that severely damaged many of the world's largest economies.

Politically, the era coincided with the rise of communism, starting in Russia with the October Revolution and Russian Civil War, at the end of WWI, and ended with the rise of fascism, particularly in Germany and Italy. China was in the midst of a half-century of instability and the Chinese Civil War between the Kuomintang, the Chinese Communist Party, and many warlords. The empires of Britain, France, and others faced challenges as imperialism was increasingly viewed negatively and independence movements emerged in many colonies; in Europe, after protracted low-level fighting most of Ireland became independent.

The Provisional Irish Republican Army (Provisional IRA), officially known as the Irish Republican Army (IRA; Irish: Óglaigh na hÉireann) and informally known as the Provos, was an Irish republican paramilitary force that sought to end British rule in Northern Ireland, facilitate Irish reunification and bring about an independent republic encompassing all of Ireland. It was the most active republican paramilitary group during the Troubles. It argued that the all-island Irish Republic continued to exist, and it saw itself as that state's army, the sole legitimate successor to the original IRA from the Irish War of Independence. It was designated a terrorist organisation in the United Kingdom and an unlawful organisation in the Republic of Ireland, both of whose authority it rejected.

The Provisional IRA emerged in December 1969, due to a split within the previous incarnation of the IRA and the broader Irish republican movement. It was initially the minority faction in the split compared to the Official IRA but became the dominant faction by 1972. The Troubles had begun shortly before when a largely Catholic, nonviolent civil rights campaign was met with violence from both Ulster loyalists and the Royal Ulster Constabulary (RUC), culminating in the August 1969 riots and deployment of British soldiers. The IRA initially focused on defence of Catholic areas, but it began an offensive campaign in 1970 that was aided by external sources, including Irish diaspora communities within the Anglosphere, and the Palestine Liberation Organization and Libyan leader Muammar Gaddafi. It used guerrilla tactics against the British Army and RUC in both rural and urban areas, and carried out a bombing campaign in Northern Ireland and England against military, political and economic targets, and British military targets in mainland Europe. They also targeted civilian contractors to the British security forces. The IRA's armed campaign, primarily in Northern Ireland but also in England and mainland Europe, killed over 1,700 people, including roughly 1,000 members of the British security forces and 500–644 civilians.

The United Kingdom constitutional law concerns the governance of the United Kingdom of Great Britain and Northern Ireland. With the oldest continuous political system on Earth, the British constitution is not contained in a single code but principles have emerged over centuries from common law statute, case law, political conventions and social consensus. In 1215, Magna Carta required the King to call "common counsel" or Parliament, hold courts in a fixed place, guarantee fair trials, guarantee free movement of people, free the church from the state, and it enshrined the rights of "common" people to use the land. After the English Civil War and the Glorious Revolution 1688, Parliament won supremacy over the monarch, the church and the courts, and the Bill of Rights 1689 recorded that the "election of members of Parliament ought to be free". The Act of Union 1707 unified England, Wales and Scotland, while Ireland was joined in 1800, but the Republic of Ireland formally separated between 1916 and 1921 through bitter armed conflict. By the Representation of the People (Equal Franchise) Act 1928, almost every adult man and woman was finally entitled to vote for Parliament. The UK was a founding member of the International Labour Organization (ILO), the United Nations, the Commonwealth, the Council of Europe, and the World Trade Organization (WTO).

The constitutional principles of parliamentary sovereignty, the rule of law, democracy and internationalism guide the UK's modern political system. The central institutions of modern government are Parliament, the judiciary, the executive, the civil service and public bodies which implement policies, and regional and local governments. Parliament is composed of the House of Commons, elected by voter constituencies, and the House of Lords which is mostly appointed on the recommendation of cross-political party groups. To make a new Act of Parliament, the highest form of law, both Houses must read, amend, or approve proposed legislation three times. The judiciary is headed by a twelve-member Supreme Court. Underneath are the Court of Appeal for England and Wales, the Court of Appeal in Northern Ireland, and the Court of Session for Scotland. Below these lie a system of high courts, Crown courts, or tribunals depending on the subject in the case. Courts interpret statutes, progress the common law and principles of equity, and can control the discretion of the executive. While the courts may interpret the law, they have no power to declare an Act of Parliament unconstitutional. The executive is headed by the Prime Minister, who must command a majority in the House of Commons. The Prime Minister appoints a cabinet of people who lead each department, and form His Majesty's Government. The King himself is a ceremonial figurehead, who gives royal assent to new laws. By constitutional convention, the monarch does not usurp the democratic process and has not refused royal assent since the Scottish Militia Bill in 1708. Beyond the Parliament and cabinet, a civil service and a large number of public bodies, from the Department of Education to the National Health Service, deliver public services that implement the law and fulfil political, economic and social rights.

The Irish Republic (Irish: Poblacht na hÉireann or Saorstát Éireann) was a revolutionary state that declared its independence from the United Kingdom of Great Britain and Ireland in January 1919. The Republic claimed jurisdiction over the whole island of Ireland, but by 1920 its functional control was limited to only 21 of Ireland's 32 counties, and British state forces maintained a presence across much of the north-east, as well as Cork, Dublin and other major towns. The republic was strongest in rural areas, and through its military forces was able to influence the population in urban areas that it did not directly control.

Its origins date back to the Easter Rising of 1916, when Irish republicans seized key locations in Dublin and proclaimed an Irish Republic. The rebellion was crushed, but the survivors united under a reformed Sinn Féin party to campaign for a republic. In the 1918 United Kingdom general election, the party won a clear majority of the constituencies in Ireland; in many seats Sinn Féin candidates did not face meaningful opposition. The Sinn Féin winners did not take their seats in the U.K. parliament, but instead gathered in Dublin on 21 January 1919 to form the first Dáil (legislature) of Ireland. Republicans then established a government, a court system and a police force. At the same time, the Irish Volunteers, who came under the control of the Dáil and became known as the Irish Republican Army, fought against British state forces in the Irish War of Independence.