De Valera issued a statement saying that "There is in Ireland at this moment only one lawful authority, and that authority is the elected Government of the Irish Republic".

When the First Dáil met in 1919, Éamon de Valera was the president of Sinn Féin and thus the natural choice for leadership. However he had been imprisoned in England so, at the meeting of the Dáil on 21 January, Cathal Brugha was elected as the first Príomh Aire on a temporary basis. De Valera escaped Lincoln Gaol in February and so was elected to replace Brugha at the Dáil's meeting on 1 April. As leader De Valera visited the United States from June 1919 to December 1920. His aim was to gain both popular and official recognition for the Republic, and to float a loan to finance Dáil Éireann and the War of Independence. By his return De Valera had won public but not official support for the Republic and had raised a loan of $6 million.

Following the outbreak of the War of Independence in January 1919, the British Government decided to suppress the Dáil, and on 10 September 1919 Dáil Éireann was declared a dangerous association and was prohibited. The Dáil continued to meet in secret, and Ministers carried out their duties as best they could. In all, the Dáil held fourteen sittings in 1919. Of these, four were public and ten private. Three private sittings were held in 1920 and four in 1921.

The First Dáil and the general election of 1918 have come to occupy a central place in Irish republicanism. The 1918 general election was the last occasion on which the entire island of Ireland voted in a single election held on a single day. The landslide victory for Sinn Féin was seen as an overwhelming endorsement of the principle of a united independent Ireland.

(First meeting 21 January) At this meeting the first temporary president was Cathal Brugha and Michael Collins, Minister for Finance. Other appointments for a parliament that were not recognised by England were:

Minister for Home Affairs: Arthur Griffith
Minister for Foreign Affairs: Count Plunkett
Minister for Defence: Cathal Brugha
Minister for Labour: Constance Markievicz
Minister for Local Government: W. T. Cosgrave
Minister for Industries: Eoin MacNeill
Minister for Irish: Seán T. O'Kelly