De valera is elected president of the first dáil éireann

Éamon de Valera; first registered as George de Valero; changed some time before 1901 to Edward de Valera; 14 October 1882 – 29 August 1975) was an Irish statesman and political leader. He served several terms as head of government and head of state and had a leading role in introducing the 1937 Constitution of Ireland.

Sinn Féin won a huge majority in the 1918 general election, largely thanks to the British executions of the 1916 leaders, the threat of conscription with the Conscription Crisis of 1918 and the first-past-the-post ballot. They won 73 out of 105 Irish seats, with about 47% of votes cast. 25 seats were uncontested. On 21 January 1919, 27 Sinn Féin MPs (the rest were imprisoned or impaired), calling themselves Teachtaí Dála (TDs), assembled in the Mansion House in Dublin and formed an Irish parliament, known as Dáil Éireann (translatable into English as the Assembly of Ireland).

The Ministry of Dáil Éireann was formed, under the leadership of the Príomh Aire (also called President of Dáil Éireann) Cathal Brugha. De Valera had been re-arrested in May 1918 and imprisoned and so could not attend the January session of the Dáil. He escaped from Lincoln Gaol, England in February 1919.

As a result, he replaced Brugha as Príomh Aire in the April session of Dáil Éireann.