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 In 1923, at a time when the home nations had withdrawn from FIFA, the FAI was recognised by FIFA as the governing body of the Irish Free State on the condition that it changed its name to the Football Association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.
Dissident Irish Republican campaign
Since the 1169 invasion of Ireland by Norman knights at the request of ousted King of Leinster Dermot MacMurrough, Ireland has, in part or in whole, been under English, and later British, administration. Rebellions against rule from Great Britain were unsuccessful until 1919–1921's Anglo-Irish War, when the original Irish Republican Army (IRA) succeeded in removing 26 of Ireland's 32 counties from the United Kingdom of Great Britain and Ireland as the Irish Free State. Although previously, the offer of Irish Home rule was agreed in the third Home Rule Bill, implementation was suspended by violent opposition in Ulster and the forming of the UVF, and later by the outbreak of the First World War. Following the partition of Ireland by the Crown, the remaining six counties, located in the province of Ulster, became Northern Ireland and remained a part of the renamed United Kingdom of Great Britain and Northern Ireland.