The newly elected Sinn Féin MP for the constituency was Cathal Brugha. Like other Sinn Féin MPs elected that year, he did not take his seat at Westminster but instead, took a seat in the revolutionary First Dáil which assembled in Dublin on 21 January 1919. As better known figures were under arrest, Brugha became the first presiding officer (with the title of Ceann Comhairle) and a day later the first head of government (with the title of President of Dáil Éireann), of the Irish Republic.
Sinn Féin contested the general election of 1918 on the platform that instead of taking up any seats they won in the United Kingdom Parliament, they would establish a revolutionary assembly in Dublin. In republican theory every MP elected in Ireland was a potential Deputy to this assembly. In practice only the Sinn Féin members accepted the offer.
The revolutionary First Dáil assembled on 21 January 1919 and last met on 10 May 1921. The First Dáil, according to a resolution passed on 10 May 1921, was formally dissolved on the assembling of the Second Dáil. This took place on 16 August 1921.