Partition of Ireland

The partition of Ireland (Irish: críochdheighilt na hÉireann) was the process by which the Government of the United Kingdom of Great Britain and Ireland (UK) divided Ireland into two self-governing polities: Northern Ireland and Southern Ireland. It was enacted on 3 May 1921 under the Government of Ireland Act 1920. The Act intended both territories to remain within the United Kingdom and contained provisions for their eventual reunification. The smaller Northern Ireland territory was created with a devolved government (Home Rule) and remained part of the UK. Although the larger Southern Ireland was also created, its administration was not recognised by most of its citizens, who instead recognised the self-declared 32-county Irish Republic.

Ireland had a largely Catholic nationalist majority who wanted self-governance or independence. Prior to partition, the Irish Parliamentary Party used its control of the balance of power in the British Parliament to persuade the government to introduce Home Rule Bills that would give Ireland a devolved government within the UK. This led to the Home Rule Crisis (1912–14), when Ulster unionists founded a large paramilitary organization (at least 100,000 men), the Ulster Volunteers, that could be used to prevent Ulster from being ruled by an Irish government. Although the Government of Ireland Act 1914 (to create a single administration) was passed, implementation was deferred due to the First World War (1914–18). Support for Irish independence grew during the war, particularly in the aftermath of the 1916 Easter Rising (an armed rebellion against British rule).

The Irish republican political party Sinn Féin won most Irish constituencies in the 1918 Westminster election. Rather than taking their seats at Westminster, the party convened a separate Irish parliament and declared an independent Irish Republic covering the whole island. This led to the Irish War of Independence (1919–21), a guerrilla conflict between the Irish Republican Army (IRA) and British forces. In 1920 the British government introduced another bill to create two devolved governments: one for six of the Ulster counties (Northern Ireland) and one for the rest of the island (Southern Ireland). This was passed as the Government of Ireland Act 1920, and came into force as a fait accompli on 3 May 1921. Following the 1921 elections, Ulster unionists formed a Northern Ireland government. During 1920–22, in what became Northern Ireland, partition was accompanied by violence in defence or opposition to the new settlement. In the first half of 1922, the IRA launched a failed "Northern Offensive" into border areas of Northern Ireland. The capital, Belfast, saw "savage and unprecedented" communal violence, mainly between Protestant and Catholic civilians. More than 500 people were killed and more than 10,000 became refugees, most of them from the Catholic minority.

The Irish War of Independence resulted in a truce in July 1921 and led to the Anglo-Irish Treaty that December. Under the Treaty, the territory of Southern Ireland would leave the UK and become the Irish Free State. Northern Ireland's parliament could vote it in or out of the Free State, and a commission could then redraw or confirm the provisional border. The Northern government chose to remain in the UK. On 6 December 1922 (a year after the signing of the Anglo-Irish Treaty), Ireland was partitioned. In 1925, the Boundary Commission proposed small changes to the border, but they were not implemented.

Since partition, most Irish nationalists/republicans continue to seek a united and independent Ireland, while Ulster unionists/loyalists want Northern Ireland to remain part of the UK. Over the years the Unionist governments of Northern Ireland have been accused of discrimination against the Irish nationalist and Catholic minority. In 1967 Unionists opposed a civil rights campaign to end discrimination, viewing it as a republican front. This helped spark the Troubles (c. 1969–1998), a thirty-year conflict in which more than 3,500 people were killed. Under the 1998 Good Friday Agreement, the Irish and British governments and the main political parties agreed to a power-sharing government in Northern Ireland, and that the status of Northern Ireland would not change without the consent of a majority of its population. The treaty also reaffirmed an open border between both jurisdictions.

During the 19th century, the Irish nationalist Home Rule movement campaigned for Ireland to have self-government while remaining part of the United Kingdom. The nationalist Irish Parliamentary Party won most Irish seats in the 1885 general election. It then held the balance of power in the British House of Commons, and entered into an alliance with the Liberals. IPP leader Charles Stewart Parnell convinced British Prime Minister William Gladstone to introduce the First Irish Home Rule Bill in 1886. Protestant unionists in Ireland opposed the Bill, fearing industrial decline and religious persecution of Protestants by a Catholic-dominated Irish government. English Conservative politician Lord Randolph Churchill proclaimed: "the Orange card is the one to play", in reference to the Protestant Orange Order. The belief was later expressed in the popular slogan, "Home Rule means Rome Rule". Partly in reaction to the Bill, there were riots in Belfast, as Protestant unionists attacked the city's Catholic nationalist minority. The Bill was defeated in the Commons.

Gladstone introduced a Second Irish Home Rule Bill in 1892. The Irish Unionist Alliance had been formed to oppose home rule, and the Bill sparked mass unionist protests. In response, Liberal Unionist leader Joseph Chamberlain called for a separate provincial government for Ulster where Protestant unionists were a majority. Irish unionists assembled at conventions in Dublin and Belfast to oppose both the Bill and the proposed partition. The unionist MP Horace Plunkett, who would later support home rule, opposed it in the 1890s because of the dangers of partition. Although the Bill was approved by the Commons, it was defeated in the House of Lords.

Following the December 1910 election, the Irish Parliamentary Party again agreed to support a Liberal government if it introduced another home rule bill. The Parliament Act 1911 meant the House of Lords could no longer veto bills passed by the Commons, but only delay them for up to two years. British Prime Minister H. H. Asquith introduced the Third Home Rule Bill in April 1912 (received Royal assent on 18 September 1914). An amendment to the Bill was introduced calling for the partition of Ireland. In June 1912 Asquith spoke in Parliament rejecting the suggestion of partition: