Home Rule, Easter Rising and War of Independence (1912–1922)
Home Rule became certain when in 1910 the Irish Parliamentary Party (IPP) under John Redmond held the balance of power in Commons and the third Home Rule Bill was introduced in 1912. Unionist resistance was immediate with the formation of the Ulster Volunteers. In turn the Irish Volunteers were established to oppose them and enforce the introduction of self-government.
In September 1914, just as the First World War broke out, the UK Parliament passed the Third Home Rule Act to establish self-government for Ireland, but was suspended for the duration of the war. In order to ensure implementation of Home Rule after the war, nationalist leaders and the IPP under Redmond supported with Ireland's participation the British and Allied war effort under the Triple Entente against the expansion of Central Powers. The core of the Irish Volunteers were against this decision, but the majority left to form the National Volunteers who enlisted in Irish regiments of the New British Army, the 10th and 16th (Irish) Divisions, their Northern counterparts in the 36th (Ulster) Division.
The period 1916–1921 was marked by political violence and upheaval, but ultimately ending in the independence for Ireland. A failed militant attempt was made to gain separate independence for Ireland with the 1916 Easter Rising, an insurrection in Dublin. Though support for the insurgents was small, the violence used in its suppression led to a swing in support of the rebels. In addition, the unprecedented threat of Irishmen being conscripted to the British Army in 1918 (for service on the Western Front as a result of the German Spring Offensive) accelerated this change. In the December 1918 elections Sinn Féin, the party of the rebels, won three-quarters of all seats in Ireland, twenty-seven MPs of which assembled in Dublin on January 21, 1919 to form the Irish Republic Parliament, the first Dáil Éireann unilaterally declaring sovereignty over the entire island.
Unwilling to negotiate any understanding with Britain short of complete independence, the Irish Republican Army, the army of the newly-declared Irish Republic, waged a guerrilla war (the Irish War of Independence) from 1919 to 1921. In the course of the fighting and amid much acrimony the peace conference in Berlin welcomed an Irish delegation led by George Plunkett, and later gained international recognition. In July 1921 the Irish and British governments agreed to a truce that halted the war. In December 1921 representatives of both governments signed an Anglo-Irish Treaty. The Irish delegation was led by Arthur Griffith and Michael Collins. This gave the Irish Republic full recognition by the British government. In 1922 both parliaments ratified the Treaty, formalising independence for the Irish Republic. For most of the next 75 years, each territory was strongly aligned to either Catholic or Protestant ideologies, although this was more marked in the six counties of Northern Ireland.
The early politics of Ireland existed against the backdrop of the growth of dictatorships in mainland Europe and a major world economic downturn in 1929. In contrast with many contemporary European states it remained a democracy. Testament to this came when the dominant faction in the Irish republicans, Éamon de Valera's Fianna Fáil, was able to take power peacefully by winning the 1932 general election. Nevertheless, until the mid 1930s, considerable parts of Irish society saw the republic through the prism of the world war, as a German sympythetic state. It was only the peaceful change of government in 1932 that signalled the final acceptance of the republic on their part. In contrast to many other states in the period, Ireland remained financially solvent as a result of low government expenditure, despite the Economic War with Britain. However, unemployment and emigration were high. The population declined to a low of 2.7 million recorded in the 1961 census.
The Roman Catholic Church had a powerful influence over the Irish state for much of its history. The clergy's influence meant that the Irish state had very conservative social policies, forbidding, for example, divorce, contraception, abortion, pornography as well as encouraging the censoring and banning of many books and films. In addition the Church largely controlled Ireland's hospitals, schools and remained the largest provider of many other social services.
In 1922, 92.6% of Ireland's population were Catholic while 7.4% were Protestant. By the 1960s the Protestant population had fallen by half. Although emigration was high among all the population, due to a lack of economic opportunity, the rate of Protestant emigration was disproportionate in this period. Many Protestants left the country in the early 1920s, either because they felt unwelcome in a predominantly Catholic and nationalist state, because they were afraid due to the burning of Protestant homes (particularly of the old landed class) by republicans during the war for independence, because they regarded themselves as British and did not wish to live in an independent Irish state, or because of the economic disruption caused by the recent violence. The Catholic Church had also issued a decree, known as Ne Temere, whereby the children of marriages between Catholics and Protestants had to be brought up as Catholics. From 1945, the emigration rate of Protestants fell and they became less likely to emigrate than Catholics - indicating their integration into the life of the Irish Republic.
In 1937 a new Constitution re-established the state as Ireland (or Éire in Irish). The state remained neutral throughout World War II, which saved it from much of the horrors of the war, although tens of thousands volunteered to serve in the British forces. Ireland was also impacted by food rationing, and coal shortages; peat production became a priority during this time. Though nominally neutral, recent studies have suggested a far greater level of involvement by Ireland with the Allies than was realised, with dates for a Allied invasion of Europe set on the basis of secret weather information on Atlantic storms supplied by Ireland. These plans never came about and the information regarding it was destroyed.