The First Dáil was elected on 18 December 1918 and first met on 21 January 1919, on which date the First Ministry assumed office, and lasted for 892 days.
In 1919 Sinn Féin candidates who had been elected in the Westminster elections of 1918 refused to recognise the Parliament of the United Kingdom and instead assembled as a unicameral, revolutionary parliament called Dáil Éireann. The first meeting of Dáil Éireann occurred on 21 January 1919 in the Round Room of the Mansion House in Dublin.
The term of office for the 1st Ministry was from 21 January – 1 April 1919. The 1st Ministry was a temporary cabinet headed by Cathal Brugha, because Éamon de Valera, the leader of Sinn Féin, was in prison at the time.
The term of office for the 2nd Ministry was from 1 April 1919 – 26 August 1921. In April 1919 de Valera became President of Dáil Éireann (Príomh Aire) and headed the 2nd Ministry. Countess Markievicz became the first Irish female Cabinet minister.