Partition

The Government of Ireland Act (1920) was designed to divide Ireland into two self-governed dominions of Britain. While the War of Independence blocked the creation of Southern Ireland, Northern Ireland, consisting of six of the nine counties of Ulster, was established in June 1921, just before the Anglo-Irish Truce was declared. The Anglo-Irish Treaty allowed for Northern Ireland to join the Free State, however, it did not take this option.

The Border

The Boundary Commission (1923-1925) was established to decide on the shape the border between the Irish Free State and Northern Ireland would take. There were expectations that there would be an exchange of land on both sides, based on the population’s politics. However, the Commission’s report did not recommend this, and the border retained its original six-county form.