Two elections in Ireland took place in 1921, as a result of the Government of Ireland Act 1920 to establish the House of Commons of Northern Ireland and the House of Commons of Southern Ireland. The election was used by Irish Republicans as the basis of membership of the Second Dáil. Where contested, the elections used Single Transferable Vote. 1921 was a common year starting on Saturday (see link for calendar). ... An Act to Provide for the Better Government of Ireland, more usually the Government of Ireland Act, 1920 (this is its official short title; the formal citation is 10 & 11 Geo. ... The Parliament of Northern Ireland was the home rule legislature created under the Government of Ireland Act 1920, which existed from June 7, 1921 to March 30, 1972, when it was suspended. ... House of Commons of Southern Ireland was the lower house of the Irish parliament created by the Government of Ireland Act, passed in 1920, during the Irish War of Independence. ... The Irish Republic (Irish: Poblacht na hÉireann or Saorstát Éireann), also known as the Republic of Ireland, was a revolutionary state established by Irish nationalists seeking secession from the United Kingdom (UK) in the 1910s, with the aim of supplanting the UK government. ... The Second Dáil was Dáil Éireann as it convened from 16th August, 1921 until 8th June, 1922. ... The Single Transferable Vote, or STV, is a preference voting system designed to minimise wasted votes in multi-candidate elections while ensuring that votes are explicitly for candidates rather than party lists. ...

The general election to the Northern Ireland House of Commons occurred on 24 May. Of 52 seats, 40 were won by Unionists, 6 by moderate nationalists and 6 by Sinn Féin. Northern Ireland is one of four constituent parts of the United Kingdom. ... May 24 is the 144th day of the year in the Gregorian calendar (145th in leap years). ... In the Irish context, Unionists form a group of largely (though not exclusively) Protestant people in Ireland, of all social classes, who wish to see the continuation of the 1801 Act of Union, as amended by the Government of Ireland Act 1920, under which the Northern Ireland provincial state created... The name Sinn Féin (pronounced in English, in Irish), which means ourselves or we ourselves (not as sometimes incorrectly translated, ourselves alone or we alone) has been applied to a series of political movements since 1905 in Ireland, each of which claim or claimed sole descent from the original...

No actual polling took place in Southern Ireland as all 128 candidates were returned unopposed. Of these, 124 were won by Sinn Féin and four by independent Unionists representing the University of Dublin (Trinity College). Southern Ireland was the twenty-six county Irish state envisaged by the Government of Ireland Act 1920. ... The College of the Holy and Undivided Trinity of Queen Elizabeth near Dublin or more commonly Trinity College, Dublin (TCD) was founded in 1592 by Queen Elizabeth I, is the only constituent college of the University of Dublin, Irelands oldest university. ...

Only Sinn Féin candidates recognised the Dáil and five of these had been elected in two constituencies (Michael Collins, Eamon de Valera, Arthur Griffith, Sean Milroy and Eoin MacNeill) one in each part of Ireland. The total number of members who assembled in the Second Dáil was 125: 119 elected solely in Southern Ireland, 1 solely in Northern Ireland (John O'Mahony), and 5 in both. Michael Collins (Irish name Micheál Ó Coileáin; October 16, 1890 – August 22, 1922), an Irish revolutionary leader, served as Minister for Finance in the Irish Republic, as a member of the Irish delegation during the Anglo-Irish Treaty negotiations, as Chairman of the Provisional Government and as Commander-in... Eamon de Valera[1] (born Edward George de Valera, Irish name Éamonn de Bhailéara (October 14, 1882 – August 29, 1975), was an Irish politician, best known as a leader of Irelands struggle for independence from Britain in the early 20th Century, and the Republican anti-Treaty opposition in... Arthur Griffith (Árt Ó Gríofa in Irish) (31 March 1871 - 12 August 1922) was the founder and first leader of Sinn Féin. ... Eoin MacNeill (May 15, 1867 - October 15, 1945) was an Irish scholar and revolutionary. ...

In Southern Ireland, there were fresh elections in 1922 as a result of the Anglo-Irish Treaty. A general election took place in southern Ireland in 16 June 1922 under the provisions of the 1921 Anglo-Irish Treaty to elect a constituent assembly paving the way for the establishment of the Irish Free State. ... Signature page of the Anglo-Irish Treaty The Anglo-Irish Treaty was a treaty between the British government and the Irish Republic which brought the Anglo-Irish War to an end and established the Irish Free State. ...