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 In 1923, at a time when the home nations had withdrawn from FIFA, the FAI was recognised by FIFA as the governing body of the Irish Free State on the condition that it changed its name to the Football Association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.
Republic of Ireland Act 1948
The UK's Ireland Act also gave a legislative guarantee that Northern Ireland would continue to remain a part of the United Kingdom unless the Parliament of Northern Ireland formally expressed a wish to join a United Ireland; this "unionist veto" proved to be controversial during the Act's passage through Westminster, as well as in the Irish state and amongst Northern Ireland's nationalist community. The guarantee was replaced in 1973, when the Parliament of Northern Ireland was abolished, by a new guarantee based on "the consent of the majority of the people of Northern Ireland".