Dáil Éireann (English: Assembly of Ireland) was the revolutionary, unicameral parliament of the unilaterally declared Irish Republic from 1919–1922. The Dáil was first formed by 73 Sinn Féin MPs elected in the 1918 United Kingdom general election. Their manifesto refused to recognise the British parliament at Westminster and chose instead to establish an independent legislature in Dublin. The convention of the First Dáil coincided with the beginning of the War of Independence.
The First Dáil was replaced by the Second Dáil in 1921. Both of these Dála existed under Irish law and it was the Second Dáil which narrowly ratified the Anglo-Irish Treaty. The status of the Third Dáil of 1922–1923 was different as it was also recognised by the British. It was elected under the terms of the 1921 Anglo-Irish Treaty as a provisional parliament to pave the way for the creation of an independent Irish state. With the establishment of the Irish Free State in 1922, a new parliament called the Oireachtas was established, of which Dáil Éireann became the lower house.