The Irish Free State (Saorstát Éireann: 6 December 1922 - 29 December 1937) was a state established in 1922 under the Anglo-Irish Treaty of December 1921 that ended the three-year Irish War of Independence.
The Free State was established as a Dominion of the British Commonwealth of Nations. It comprised 26 of the 32 counties of Ireland. Northern Ireland, which comprised the remaining six counties, exercised its right under the Treaty to opt out of the new state.
Pro-Treaty members, who formed Cumann na nGaedheal in 1923, held an effective majority in the Dáil from 1922 to 1927, and thereafter ruled as a minority government until 1932.
In 1931, with the passage of the Statute of Westminster, the Parliament of the United Kingdom relinquished its remaining authority to legislate for the Free State and the other dominions. This had the effect of making the dominions fully sovereign states. The Free State thus became the first internationally recognised independent Irish state.
In 1926 Sinn Féin president, Éamon de Valera, resigned from Sinn Féin and founded Fianna Fáil. Fianna Fáil entered the Dáil following the 1927 general election, and entered government after the Irish general election, 1932, when it became the largest party.
De Valera abolished the Oath of Allegiance and embarked on an economic war with the UK. In 1937 he drafted a new constitution, which was passed by a referendum in July of that year. The Free State legally came to an end with the coming into force of a new constitution on 29 December 1937 when the state took the name “Ireland”.