United Kingdom of Great Britain and Ireland (Central Victory)

Edwardian era 1901–1914
Queen Victoria died in 1901 and her son Edward VII became king, inaugurating the Edwardian Era, which was characterised by great and ostentatious displays of wealth in contrast to the sombre Victorian Era. With the advent of the 20th century, things such as motion pictures, automobiles, and aeroplanes were coming into use. The new century was characterised by a feeling of great optimism. The social reforms of the last century continued into the 20th with the Labour Party being formed in 1900. Edward died in 1910, to be succeeded by George V, who reigned 1910–36. Scandal-free, hard working and popular, George V was the British monarch who, with Queen Mary, established the modern pattern of exemplary conduct for British royalty, based on middle-class values and virtues. He understood the overseas Empire better than any of his prime ministers and used his exceptional memory for figures and details, whether of uniforms, politics, or relations, to good effect in reaching out in conversation with his subjects.

The era was prosperous but political crises were escalating out of control. Dangerfield (1935) identified the "strange death of liberal England" as the multiple crisis that hit simultaneously in 1910–1914 with serious social and political instability arising from the Irish crisis, labor unrest, the women's suffrage movements, and partisan and constitutional struggles in Parliament. At one point it even seemed the Army might refuse orders dealing with Northern Ireland. No solution appeared in sight when the unexpected outbreak of the Great War in 1914 put domestic issues on hold. McKibben argues that the political party system of the Edwardian era was in delicate balance on the eve of the war in 1914. The Liberals were in power with a progressive alliance of Labour and, off and on, Irish Nationalists. The coalition was committed to free trade (as opposed to the high tariffs the Conservatives sought), free collective bargaining for trades unions (which Conservatives opposed), an active social policy that was forging the welfare state, and constitutional reform to reduce the power of the House of Lords. The coalition lacked a long-term plan, because it was cobbled together from leftovers from the 1890s. The sociological basis was non-Anglicanism and non-English ethnicity rather than the emerging class conflict emphasized by the Labour Party.

World War I
After a rough start Britain under David Lloyd George successfully mobilised its manpower, industry, finances, Empire and diplomacy, in league with the French, to defeat the Germans and Turks. A segment of extreme Irish nationalists had infiltrated Eoin MacNeill's Irish Volunteers, and plotted a rebellion in 1916. The economy grew by about 14% from 1914–18 despite the absence of so many men in the services; by contrast the German economy shrank 27%. The Great War saw a decline in civilian consumption, with a major reallocation to munitions. The government share of GDP soared from 8% in 1913 to 38% in 1918. The war forced Britain to use up its financial reserves and borrow large sums from the U.S.

The spark that set off the war came in June 1914, when the multi-ethnic Austrian Empire declared war on Serbia after Serb guerrillas murdered the Archduke and his wife. The system of alliances caused a local conflict to engulf the entire continent. Britain was part of the Triple Entente with France and Russia, which confronted the Central Powers of Germany, Austria and Italy. Following the assassination Austria attacked Serbia, which was allied to Russia. Russia then mobilized its army, leading Germany to enter into war against Russia. France could not afford a mobilized Germany on its border, and it mobilized. Germany declared war on France. Britain was neutral at first as the Liberal government had a pacifist tendency, but it was committed to defending Belgium, which Germany invaded. Britain declared war on Germany and its allies. The romantic notions of warfare that everyone had expected faded as the fighting in France bogged down into trench warfare. Along the Western Front the British and French launched repeated assaults on the German trench lines in 1915–16, which killed and wounded hundreds of thousands, but failed to make gains of even a mile. By 1916, with volunteers falling off, the government imposed conscription in Britain (but was not able to do so in Ireland where nationalists of all stripes militantly opposed it) in order to keep up the strength of the Army. Industry turned out munitions in large quantities, with many women taking factory jobs. The Asquith government proved ineffective but when David Lloyd George replaced him in December 1916 Britain gained a powerful wartime leader.

The Navy continued to dominate the seas, fighting the German fleet to a draw in the only great battle, the Battle of Jutland in 1916. Germany was blockaded and was increasingly short of food until the Action of August 19, 1916 resulting in the German Navy breaking the blockade. It tried to fight back with submarines, despite the risk of war by the powerful neutral power the United States. The waters around Britain were declared a war zone where any ship, neutral or otherwise, was a target. After the liner Lusitania was sunk in May 1915, drowning over 100 American passengers, protests by the United States led Germany to abandon unrestricted submarine warfare. With victory over Russia in 1917 Germany now calculated it could finally have numerical superiority on the Western Front. Planning for a massive spring offensive in 1918. On other fronts, the British, French, Australians, and Japanese occupied Germany's colonies. Britain fought the Ottoman Empire, suffering defeats in the Gallipoli Campaign) and in Mesopotamia, while arousing the Arabs who helped expel the Turks from their lands. Exhaustion and war weariness were growing worse in 1917, as the fighting in France continued with no end in sight. The German spring offensives of 1918 succeeded, and with the ongoing conscription crisis in Ireland the British government realized they were being overwhelmed. Britain and its allies agreed to an armistice on August 11, 1918. The war had been lost, at a terrible human and financial cost, creating a sentiment that wars should never be fought again. The harsh peace settlement imposed on most of the allies would leave them embittered and seeking revenge.

Victorian attitudes and ideals that had continued into the first years of the 20th century changed during World War I. The army had traditionally never been a large employer in the nation, with the regular army standing at 247,432 at the start of the war. By 1918, there were about five million people in the army and the fledgling Royal Air Force, newly formed from the Royal Naval Air Service (RNAS) and the Royal Flying Corps (RFC), was about the same size of the pre-war army. The almost three million casualties were known as the "lost generation," and such numbers inevitably left society scarred; but even so, some people felt their sacrifice was little regarded in Britain, with poems like Siegfried Sassoon's Blighters criticising the ill-informed "jingoism" of the Home Front.

Following the war, Britain gained Palestine, which was turned into a homeland for Jewish settlers, and Iraq, created from the three Ottoman provinces in Mesopotamia; the latter of which became fully independent in 1932. Egypt, which had been a British protectorate since 1882, became independent in 1922, although the British remained there until 1952. Lloyd George said after the war that "the nation was now in a molten state",  and his Housing Act of 1919 would lead to affordable council housing which allowed people to move out of Victorian inner-city slums. The slums remained for several more years, with trams being electrified long before many houses. The Representation of the People Act 1918 gave women householders the vote, but it would not be until 1928 that equal suffrage was achieved. Labour did not achieve major success until the 1922 general election.

Anglo-Irish War/Irish Civil War
The European situation combined with the threat of conscription (which had been operating in Great Britain but had not yet been introduced into Ireland) changed the political climate further. In the Irish general election of December 1918, the Irish Parliamentary Party (IPP) lost all but six of its seats to the more radical nationalist party, Sinn Féin. (John Redmond, the leader of the IPP, had died earlier that year, and his successor, John Dillon, son of the noted Young Irelander John Blake Dillon, lost his own seat.) Unionists won the remainder of the seats, almost exclusively in the six counties of Ulster, which would later become Northern Ireland. The Sinn Féin "MPs" (some, like Laurence Ginnell, having formerly been members of the IPP), campaigned as abstentionists, refusing to participate at Westminster. In January 1919 a unilaterally independent Irish parliament was formed in Dublin, known as the first "Dáil Éireann", with an executive under the President of Dáil Éireann, Éamon de Valera, a leader of the Easter Rising of 1916, who had avoided execution due to his birth in New York. (Although de Valera never made any claim to U.S. citizenship, Britain, struggling in the midst of World War I, could not afford to estrange itself from the United States, which did not formally enter the Great War.)

A War of Independence was fought between 1919 and 1921, largely led by Michael Collins, who employed unorthodox guerrilla and counter-intelligence tactics which inflicted heavy damage on both the local police (the Royal Irish Constabulary, or RIC) as well as British intelligence agents in Dublin, undermining British morale, although Collins reportedly later told the British: "You had us dead beat. We could not have lasted another three weeks. When we were told of the offer of a truce we were astounded. We thought you must have gone mad." A treaty between the British government and representatives of the Dáil was finally agreed in l922, which resulted in the partition of the island of Ireland on May 3, 1921 under the Government of Ireland Act 1920 into two distinct autonomous United Kingdom regions, Northern Ireland and the short-lived Southern Ireland. Although the new Dominion status granted Irish nationalists far more autonomy than had been sought by the IPP, it was unacceptable to hard-liners who opposed the treaty (Fianna Fáil). A civil war was fought, which the pro-treaty (Fine Gael) forces finally won in 1923. Michael Collins was assassinated on August 22, 1922 in his native County Cork.

On December 6, 1922 a year after the Anglo-Irish Treaty was signed, the entire island of Ireland effectively seceded from the United Kingdom of Great Britain and Ireland, forming a new dominion, the Irish Free State. As was widely expected, the area known as "Northern Ireland" (six counties in Ulster) immediately exercised its right under the Anglo-Irish Treaty, to opt-out of the Irish Free State. On December 7, 1922 the day after the establishment of the Irish Free State, the Parliament of Northern Ireland made an address to King George V to opt out of the Irish Free State, which the King accepted. The surviving Union of Great Britain with part of Ireland continued to be called the "United Kingdom of Great Britain and Ireland" until 1927, when it was renamed United Kingdom of Great Britain and Northern Ireland by the Royal and Parliamentary Titles Act 1927, and is known by this name to the present time.

Independence of the Irish Free State
In 1919, the majority of Irish MPs refused to recognise the Parliament of the United Kingdom and formed a unilaterally independent Irish parliament, Dáil Éireann, with an executive under the President of Dáil Éireann, Eamon de Valera. A War of Independence was fought between 1919 and 1921. Finally in December 1922, twenty-six of Ireland's counties exited from the United Kingdom of Great Britain and Ireland and formed an independent Irish Free State. The southern part of Ireland that seceded from the union is today the Republic of Ireland. It covers the same territory as the Free State, but adopted a new constitution in 1937. Six counties in Ulster, called Northern Ireland, remain a part of the continuing United Kingdom, which was renamed the United Kingdom of Great Britain and Northern Ireland in 1927, in accordance with the Royal and Parliamentary Titles Act 1927.

Partition of Ireland
The Anglo-Irish Treaty was given effect in the whole of the British Isles through the Irish Free State Constitution Act 1922. That Act established a new Dominion for the whole island of Ireland but also allowed Northern Ireland to opt out of it. Under Article 12 of the Treaty, Northern Ireland could exercise its opt out by presenting an address to the King requesting not to be part of the Irish Free State. Once the Treaty was ratified, the Houses of Parliament of Northern Ireland had one month to exercise this opt out during which month the Irish Free State Government could not legislate for Northern Ireland, holding the Free State's effective jurisdiction in abeyance for a month.

On December 7, 1922 (the day after the establishment of the Irish Free State) the Houses of Parliament demonstrated its lack of hesitation by resolving to make the following address to the King to opt out of the Irish Free State:"MOST GRACIOUS SOVEREIGN, We, your Majesty's most dutiful and loyal subjects, the Senators and Commons of Northern Ireland in Parliament assembled, having learnt of the passing of the Irish Free State Constitution Act, 1922, being the Act of Parliament for the ratification of the Articles of Agreement for a Treaty between Great Britain and Ireland, do, by this humble Address, pray your Majesty that the powers of the Parliament and Government of the Irish Free State shall no longer extend to Northern Ireland."

On December 13, 1922 Prime Minister James Craig addressed the Parliament of Northern Ireland, informing them that the King had responded to the Parliament's address as follows (the King having received it on 8 December 1922): "I have received the Address presented to me by both Houses of the Parliament of Northern Ireland in pursuance of Article 12 of the Articles of Agreement set forth in the Schedule to the Irish Free State (Agreement) Act, 1922, and of Section 5 of the Irish Free State Constitution Act, 1922, and I have caused my Ministers and the Irish Free State Government to be so informed."

Legacy
Despite increasing political independence from each other from 1922 and complete political independence since the new constitution of 1937, the union left the two countries intertwined with each other in many respects. The Irish Free State, as it was then known, used the Irish pound (known colloquially as the "punt") from 1928 until 2001, when the euro replaced it. Until joining the ERM in 1979, the Irish pound was directly linked to the pound sterling. Decimalisation of both currencies occurred simultaneously on Decimal Day in 1971. Coins of equivalent value had the same dimensions and size until the introduction of the British twenty pence coin in 1982. British coinage, therefore, although technically not legal tender in the Republic of Ireland was in wide circulation and usually acceptable as payment, and vice versa. The new British twenty pence coin and later British one pound coin were the notable exceptions to this, as there was initially no equivalent Irish coin value, and when subsequently, Irish coins of these values were introduced, their designs differed significantly, thereby not allowing for 'stealth' passing of the coins in change.

Irish citizens in the UK have a status almost equivalent to British citizens. They can vote in all elections and stand for Parliament. British citizens have similar rights to Irish citizens in the Republic of Ireland and can vote in all elections apart from presidential elections and referendums.

Under the Irish nationality law anyone born on the island of Ireland to a British or Irish parent can have Irish citizenship and so most children born in Northern Ireland can have a British or an Irish passport (or both). Before 2005 there was no requirement for one parent to be a British or Irish citizen and so all persons born on the island of Ireland before then are entitled to be Irish citizens.