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 In 1923, at a time when the home nations had withdrawn from FIFA, the FAI was recognised by FIFA as the governing body of the Irish Free State on the condition that it changed its name to the Football Association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.
Ulster
Partition of Ireland, first mooted in 1912, was introduced with the enactment of the Government of Ireland Act 1920, which gave a form of "Home rule" self-government to two areas, Southern Ireland, with its capital at Dublin, and "Northern Ireland", consisting of six of Ulster's central and eastern counties, both within a continuing United Kingdom of Great Britain and Ireland. Dissatisfaction with this led to the Irish War of Independence, which formally ceased on 11 July 1921. Low-level violence, however, continued in Ulster, causing Michael Collins in the south to order a boycott of Northern products in protest at attacks on the Nationalist community there. The Partition was effectively confirmed by the Anglo-Irish Treaty of 6 December 1921. One of the primary stipulations of the treaty was the transformation of Ireland into a self-governing British dominion called the Irish Free State (which later became the sovereign Republic of Ireland), but with the option of a continuation of the home rule institution of Northern Ireland, still within the United Kingdom, if the Northern Ireland Parliament (already in existence) chose to opt out of the Irish Free State. All parties knew that this was certain to be the choice of the Ulster Unionists who had a majority in the parliament, and immediately on the creation of the Free State they resolved to leave it.