Sinn Féin for nine years. (It merged with two other organisations to form Fine Gael in 1933.) Anti-Treaty Sinn Féin members continued to boycott the Dáil. At a special "Ard Fheis" in March 1926, de Valera proposed that elected members be allowed to take their seats in the Dáil if and when the controversial Oath of Allegiance was removed. When his motion was defeated, de Valera resigned from Sinn Féin; on 16 May 1926, he founded his own party, Fianna Fáil, which was dedicated to republicanising the Free State from within its political structures. He took most Sinn Féin TDs with him.
Éamon de Valera the work of Michael Collins and based on three sources: British oaths in the dominions, the oath of the Irish Republican Brotherhood and a draft oath prepared by de Valera in his proposed Treaty alternative, "Document No. 2"). De Valera began a legal case to challenge the requirement that members of his party take the Oath, but the assassination of the Vice-President of the Executive Council (deputy prime minister) Kevin O'Higgins on 10 July 1927 led the Executive Council under W. T. Cosgrave to introduce a Bill on 20 July requiring all Dáil candidates to promise on oath that if