Northern Ireland national football team
In 1920, Ireland was partitioned into Northern Ireland and Southern Ireland. In 1922, Southern Ireland gained independence as the Irish Free State, later to become a republic under the name of Ireland. Amid these political upheavals, a rival football association, the Football Association of Ireland, emerged in Dublin in 1921 and organised a separate league and international team. In 1923, at a time when the home nations had withdrawn from FIFA, the FAI was recognised by FIFA as the governing body of the Irish Free State on the condition that it changed its name to the Football Association of the Irish Free State. The Irish FA continued to organise its national team on an all-Ireland basis.
Northern Ireland
Events overtook the government. The pro-independence Sinn Féin won 73 of the 105 parliamentary seats in Ireland at the general election of 1918, and unilaterally established the First Dáil, an extrajudicial parliament in Ireland. Ireland was partitioned between Northern Ireland and Southern Ireland in 1921, under the terms of Lloyd George's Government of Ireland Act 1920, during the Anglo-Irish War between Irish republican and British forces. A truce was established on 11 July; the war ended on 6 December 1921 with the signing of the Anglo-Irish Treaty, which created the Irish Free State. Under the terms of the treaty, Northern Ireland would become part of the Free State unless the government opted out by presenting an address to the king, although in practice partition remained in place.